U.S. patent application number 15/464559 was filed with the patent office on 2017-11-16 for display device.
The applicant listed for this patent is InnoLux Corporation. Invention is credited to Hui-Chi WANG.
Application Number | 20170331008 15/464559 |
Document ID | / |
Family ID | 60297564 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170331008 |
Kind Code |
A1 |
WANG; Hui-Chi |
November 16, 2017 |
DISPLAY DEVICE
Abstract
A display device is provided. The display device includes a
substrate and a light-emitting diode. The light-emitting diode
includes first and second conductive-type semiconductor layers and
a light-emitting layer. The second conductive-type semiconductor
layer is adjacent to the substrate. The first conductive-type
semiconductor layer includes a bulk portion and a reflection layer
disposed over a side of the bulk portion. The bulk portion has a
first surface away from the light-emitting layer and a second
surface adjacent to the light-emitting layer. The second
conductive-type semiconductor layer has a third surface adjacent to
the light-emitting layer and a fourth surface away from the
light-emitting layer. There is a specific relationship between the
width of the first surface, the width of the light-emitting layer,
the distance from the first surface to the fourth surface, and the
distance from the first surface to the light-emitting layer.
Inventors: |
WANG; Hui-Chi; (Miao-Li
County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
InnoLux Corporation |
Miao-Li County |
|
TW |
|
|
Family ID: |
60297564 |
Appl. No.: |
15/464559 |
Filed: |
March 21, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 29/8613 20130101;
H01L 33/32 20130101; H01L 33/20 20130101; H01L 33/24 20130101; H01L
33/38 20130101; H01L 33/46 20130101; H01L 33/06 20130101 |
International
Class: |
H01L 33/46 20100101
H01L033/46; H01L 29/861 20060101 H01L029/861; H01L 33/38 20100101
H01L033/38; H01L 33/32 20100101 H01L033/32; H01L 33/24 20100101
H01L033/24; H01L 33/20 20100101 H01L033/20; H01L 33/06 20100101
H01L033/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 11, 2016 |
CN |
201610307720.1 |
Claims
1. A display device, comprising: a substrate; a light-emitting
diode disposed over the substrate, wherein the light-emitting diode
comprises: a first conductive-type semiconductor layer, a
light-emitting layer and a second conductive-type semiconductor
layer, wherein the light-emitting layer is disposed between the
first conductive-type semiconductor layer and the second
conductive-type semiconductor layer, wherein the second
conductive-type semiconductor layer is adjacent to the substrate,
wherein the first conductive-type semiconductor layer comprises a
bulk portion and a reflection layer disposed over a side of the
bulk portion, wherein the bulk portion has a first surface away
from the light-emitting layer and a second surface adjacent to the
light-emitting layer, and the second conductive-type semiconductor
layer has a third surface adjacent to the light-emitting layer and
a fourth surface away from the light-emitting layer; wherein when
viewed from a cross-sectional view, a width of the first surface is
width D1, a width of the light-emitting layer is width D2, a
distance from the first surface to the fourth surface is distance
H1, and a distance from the first surface to the light-emitting
layer is distance H2, wherein 0.269 .ltoreq. ( D 2 .times. H 2 ) (
D 1 .times. H 1 ) .ltoreq. 0.857 . ##EQU00005##
2. The display device as claimed in claim 1, wherein a width of the
fourth surface is width D3, and the width D2 of the light-emitting
layer is represented by the following equation: D 2 = ( H 1 - H 2 )
.times. ( D 1 - D 3 ) H 1 + D 3. ##EQU00006##
3. The display device as claimed in claim 1, wherein a direction
perpendicular to the first surface of the bulk portion is a first
direction, wherein when viewed from a cross-sectional view, an
acute angle between a first sidewall of the bulk portion and the
first direction is a first angle, and the first angle ranges from
about 1 to 89 degrees.
4. The display device as claimed in claim 3, wherein when viewed
from a cross-sectional view, the bulk portion further comprises a
second sidewall, and the first sidewall and the second sidewall are
opposite to each other, wherein an acute angle between the second
sidewall of the bulk portion and the first direction is a second
angle, and the second angle is substantially the same as the first
angle.
5. The display device as claimed in claim 3, wherein when viewed
from a cross-sectional view, the bulk portion further comprises a
second sidewall, and the first sidewall and the second sidewall are
opposite to each other, wherein an acute angle between the second
sidewall of the bulk portion and the first direction is a second
angle, and the second angle is different from the first angle.
6. The display device as claimed in claim 1, wherein an area of the
first surface is greater than an area of the fourth surface.
7. The display device as claimed in claim 1, further comprising: a
first electrode electrically connected to the first conductive-type
semiconductor a second electrode electrically connected to the
second conductive-type semiconductor layer.
8. The display device as claimed in claim 7, wherein the second
electrode completely covers the fourth surface of the second
conductive-type semiconductor layer.
9. The display device as claimed in claim 7, wherein the first
electrode is disposed over a surface of the first conductive-type
semiconductor layer.
10. The display device as claimed in claim 1, further comprising:
an insulating layer disposed between the reflection layer and the
bulk portion.
11. The display device as claimed in claim 1, wherein the
reflection layer is in direct contact with the bulk portion.
12. The display device as claimed in claim 7, wherein the
reflection layer is electrically isolated from the second
electrode.
13. The display device as claimed in claim 1, wherein the
reflection layer is further disposed over a sidewall of the second
conductive-type semiconductor layer, wherein the reflection layer
disposed over the sidewall of the bulk portion is not electrically
connected to the reflection layer disposed over the sidewall of the
second conductive-type semiconductor layer.
14. The display device as claimed in claim 1, wherein the
reflection layer comprises a plurality of sub-reflection layers,
and the plurality of sub-reflection layers are not electrically
connected to each other.
15. The display device as claimed in claim 1, wherein the
reflection layer has a thickness which is gradually changed.
16. The display device as claimed in claim 15, wherein a sidewall
of the reflection layer is perpendicular to the first surface.
17. The display device as claimed in claim 15, wherein a surface of
the reflection layer has a height that is substantially the same as
that of the fourth surface.
18. The display device as claimed in claim 1, wherein when viewed
from a cross-sectional view, the first conductive-type
semiconductor layer further comprises: a substrate portion and two
pillar portions, wherein the two pillar portions is disposed over
the substrate portion, and the two pillar portions and the
substrate portion forms a recess, wherein the bulk portion is
disposed in the recess.
19. The display device as claimed in claim 18, wherein the
reflection layer is disposed in a spacing between the bulk portion
and a sidewall of the recess.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of China Patent Application
No. 201610307720.1, filed on May 11, 2016, the entirety of which is
incorporated by reference herein.
BACKGROUND
Field of the Invention
[0002] The disclosure relates to a display device, and in one
embodiment to a display device having a light-emitting diode
chip.
Description of the Related Art
[0003] As digital technology develops, display devices are becoming
more widely used in our society. For example, display devices have
been applied in modern information and communication devices such
as televisions, notebooks, computers, mobile phones, and
smartphones. In addition, each generation of display devices has
been developed to be thinner, lighter, smaller, and more
fashionable than the last. These display devices include
light-emitting diode display devices.
[0004] The recombination radiation of electron and hole in the
light-emitting diode may produce electromagnetic radiation (such as
light) through the current at the p-n junction. For example, in a
forward bias p-n junction formed by direct band gap materials such
as GaAs or GaN, the recombination of electron and hole injected
into the depletion region results in electromagnetic radiation such
as light. The aforementioned electromagnetic radiation may lie in
the visible region or the non-visible region. Materials with
different band gaps may be used to form light-emitting diodes of
different colors.
[0005] Since mass production has recently become the tendency in
the light-emitting diode industry, any increase in the yield of
manufacturing light-emitting diodes will reduce costs and result in
huge economic benefits. However, existing display devices have not
been satisfactory in every respect. For example, when the
light-emitting view angle and the light-emitting shape of the
light-emitting diode display device have to be altered, an
additional second lens layer needs to be disposed over the
light-emitting surface. However, this greatly increases the
cost.
[0006] Therefore, a display device which may alter the
light-emitting view angle and the light-emitting shape freely or
may improve the light-emitting effectiveness is needed.
BRIEF SUMMARY
[0007] The present disclosure provides a display device, including:
a substrate; a light-emitting diode disposed over the substrate,
wherein the light-emitting diode includes: a first conductive-type
semiconductor layer, a light-emitting layer and a second
conductive-type semiconductor layer, wherein the light-emitting
layer is disposed between the first conductive-type semiconductor
layer and the second conductive-type semiconductor layer, wherein
the second conductive-type semiconductor layer is adjacent to the
substrate, wherein the first conductive-type semiconductor layer
includes a bulk portion and a reflection layer disposed over a side
of the bulk portion, wherein the bulk portion has a first surface
away from the light-emitting layer and a second surface adjacent to
the light-emitting layer, and the second conductive-type
semiconductor layer has a third surface adjacent to the
light-emitting layer and a fourth surface away from the
light-emitting layer. When viewed from a cross-sectional view,
there is a specific relationship between the width of the first
surface, the width of the light-emitting layer, the distance from
the first surface to the fourth surface, and the distance from the
first surface to the light-emitting layer.
[0008] A detailed description is given in the following embodiments
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The disclosure may be more fully understood by reading the
subsequent detailed description and examples with references made
to the accompanying drawings, wherein:
[0010] FIG. 1A is a cross-sectional view of a display device in
accordance with some embodiments of the present disclosure;
[0011] FIG. 1B is a cross-sectional view of a display device in
accordance with some embodiments of the present disclosure;
[0012] FIG. 2A is a cross-sectional view of the reflection layer in
accordance with some embodiments of the present disclosure;
[0013] FIG. 2B is a cross-sectional view of the reflection layer in
accordance with some embodiments of the present disclosure;
[0014] FIG. 3 is an analytical figure of the ratio of specific
width and distance in the stack structure versus the half width at
half maximum in accordance with some embodiments of the present
disclosure;
[0015] FIG. 4A is a schematic view of the stack structure in
accordance with some embodiments of the present disclosure;
[0016] FIG. 4B is an analytical figure of the width of the bottom
surface of the stack structure versus the half width at half
maximum in accordance with some embodiments of the present
disclosure;
[0017] FIG. 4C is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0018] FIG. 4D is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0019] FIG. 4E is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0020] FIG. 4F is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0021] FIG. 4G is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0022] FIG. 5A is a schematic view of the stack structure in
accordance with some embodiments of the present disclosure;
[0023] FIG. 5B is an analytical figure of the width of the major
axis at the bottom surface of the stack structure versus the half
width at half maximum in accordance with some embodiments of the
present disclosure;
[0024] FIG. 5C is an analytical figure of the width of the minor
axis at the bottom surface of the stack structure versus the half
width at half maximum in accordance with some embodiments of the
present disclosure;
[0025] FIG. 5D is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0026] FIG. 5E is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0027] FIG. 5F is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0028] FIG. 5G is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0029] FIG. 5H is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0030] FIG. 6A is a schematic view of the stack structure in
accordance with some embodiments of the present disclosure;
[0031] FIG. 6B is an analytical figure of the width of the bottom
surface of the stack structure versus the half width at half
maximum in accordance with some embodiments of the present
disclosure;
[0032] FIG. 6C is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0033] FIG. 6D is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0034] FIG. 6E is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0035] FIG. 6F is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0036] FIG. 6G is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0037] FIG. 7A is a schematic view of the stack structure in
accordance with some embodiments of the present disclosure;
[0038] FIG. 7B is an analytical figure of the width of the major
axis at the bottom surface of the stack structure versus the half
width at half maximum in accordance with some embodiments of the
present disclosure;
[0039] FIG. 7C is an analytical figure of the width of the minor
axis at the bottom surface of the stack structure versus the half
width at half maximum in accordance with some embodiments of the
present disclosure;
[0040] FIG. 7D is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0041] FIG. 7E is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0042] FIG. 7F is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0043] FIG. 7G is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0044] FIG. 7H is a distribution figure of the emitted light at
various view angles in accordance with some embodiments of the
present disclosure;
[0045] FIG. 8A is a cross-sectional view of the stack structure in
accordance with some embodiments of the present disclosure;
[0046] FIG. 8B is a cross-sectional view of the stack structure in
accordance with some embodiments of the present disclosure;
[0047] FIG. 9A is a cross-sectional view of a display device in
accordance with some other embodiments of the present
disclosure;
[0048] FIG. 9B is a cross-sectional view of a display device in
accordance with some other embodiments of the present disclosure;
and
[0049] FIG. 9C is a cross-sectional view of a display device in
accordance with some other embodiments of the present
disclosure.
DETAILED DESCRIPTION
[0050] The display device of the present disclosure is described in
detail in the following description. In the following detailed
description, for purposes of explanation, numerous specific details
and embodiments are set forth in order to provide a thorough
understanding of the present disclosure. The specific elements and
configurations described in the following detailed description are
set forth in order to clearly describe the present disclosure. It
will be apparent, however, that the exemplary embodiments set forth
herein are used merely for the purpose of illustration, and the
inventive concept may be embodied in various forms without being
limited to those exemplary embodiments. In addition, the drawings
of different embodiments may use like and/or corresponding numerals
to denote like and/or corresponding elements in order to clearly
describe the present disclosure. However, the use of like and/or
corresponding numerals in the drawings of different embodiments
does not suggest any correlation between different embodiments. In
addition, in this specification, expressions such as "first
material layer disposed on/over a second material layer", may
indicate the direct contact of the first material layer and the
second material layer, or it may indicate a non-contact state with
one or more intermediate layers between the first material layer
and the second material layer. In the above situation, the first
material layer may not be in direct contact with the second
material layer.
[0051] In addition, in this specification, relative expressions are
used. For example, "lower", "bottom", "higher" or "top" are used to
describe the position of one element relative to another. It should
be appreciated that if a device is flipped upside down, an element
that is "lower" will become an element that is "higher".
[0052] The terms "about" and "substantially" typically mean +/-20%
of the stated value, more typically +/-10% of the stated value,
more typically +/-5% of the stated value, more typically +/-3% of
the stated value, more typically +/-2% of the stated value, more
typically +/-1% of the stated value and even more typically +/-0.5%
of the stated value. The stated value of the present disclosure is
an approximate value. When there is no specific description, the
stated value includes the meaning of "about" or
"substantially".
[0053] It should be understood that, although the terms first,
second, third etc. may be used herein to describe various elements,
components, regions, layers, portions and/or sections, these
elements, components, regions, layers, portions and/or sections
should not be limited by these terms. These terms are only used to
distinguish one element, component, region, layer, portion or
section from another region, layer or section. Thus, a first
element, component, region, layer, portion or section discussed
below could be termed a second element, component, region, layer,
portion or section without departing from the teachings of the
present disclosure.
[0054] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this disclosure belongs. It
should be appreciated that, in each case, the term, which is
defined in a commonly used dictionary, should be interpreted as
having a meaning that conforms to the relative skills of the
present disclosure and the background or the context of the present
disclosure, and should not be interpreted in an idealized or overly
formal manner unless so defined.
[0055] This description of the exemplary embodiments is intended to
be read in connection with the accompanying drawings, which are to
be considered part of the entire written description. The drawings
are not drawn to scale. In addition, structures and devices are
shown schematically in order to simplify the drawing.
[0056] In the description, relative terms such as "lower," "upper,"
"horizontal," "vertical,", "above," "below," "up," "down," "top"
and "bottom" as well as derivative thereof (e.g., "horizontally,"
"downwardly," "upwardly," etc.) should be construed to refer to the
orientation as then described or as shown in the drawing under
discussion. These relative terms are for convenience of description
and do not require that the apparatus be constructed or operated in
a particular orientation. Terms concerning attachments, coupling
and the like, such as "connected" and "interconnected," refer to a
relationship wherein structures are secured or attached to one
another either directly or indirectly through intervening
structures, as well as both movable or rigid attachments or
relationships, unless expressly described otherwise.
[0057] The term "substrate" is meant to include devices formed
within a transparent substrate and the layers overlying the
transparent substrate. All needed transistor elements may already
be formed over the substrate. However, the substrate is represented
with a flat surface in order to simplify the drawing. The term
"substrate surface" is meant to include the uppermost exposed
layers on a transparent substrate, such as an insulating layer
and/or metallurgy lines. The material of the substrate may include
glass, plastic or any other materials or layers which the wires or
transistor elements may be formed on, such as polyimide (PI). The
substrate may also be a flexible substrate.
[0058] In some embodiments of the present disclosure, since the
specific width and distance in the stack structure of the
light-emitting diode have a specific relationship, the
light-emitting diode display device in some embodiments of the
present disclosure may alter the light-emitting view angle and the
light-emitting shape freely and/or may improve the light-emitting
effectiveness.
[0059] FIG. 1A is a cross-sectional view of a display device 100 in
accordance with some embodiments of the present disclosure. As
shown in FIG. 1A, the display device 100 includes a substrate 102
and a light-emitting diode 104 disposed over the substrate 102. In
some embodiments of the present disclosure, the substrate 102 may
include a thin film transistor substrate.
[0060] The light-emitting diode 104 may include the first
conductive-type semiconductor layer 106. The first conductive-type
semiconductor layer 106 has a substrate portion 106A and a bulk
portion 106B disposed over the substrate portion 106A. The bulk
portion 106B has a first surface S1 adjacent to the substrate
portion 106A and a second surface S2 away from the substrate
portion 106A. In other embodiments of the present disclosure, the
first conductive-type semiconductor layer 106 may only have a bulk
portion 106B and may not have a substrate portion 106A. The bulk
portion 106B may be in direct contact with the conductive
electrode. In this embodiment, the first surface S1 is the bottom
surface of the bulk portion 106B. In this embodiment, the interface
separating the bulk portion 106B and the substrate portion 106A
serves as the datum surface of the bottom surface of the bulk
portion 106B. The datum surface is substantially parallel to the
surface of the substrate portion 106A. In this embodiment, the
datum surface is a portion of the surface of substrate portion
106A.
[0061] The light-emitting diode 104 may further include a
light-emitting layer 108 disposed over the second surface S2 of the
bulk portion 106B of the first conductive-type semiconductor layer
106, and a second conductive-type semiconductor layer 110 disposed
over the light-emitting layer 108. In other words, the
light-emitting layer 108 is disposed between the first
conductive-type semiconductor layer 106 and the second
conductive-type semiconductor layer 110. The second conductive-type
semiconductor layer 110 is adjacent to the substrate 102. In
addition, as shown in FIG. 1A, the first surface S1 of the bulk
portion 106B of the first conductive-type semiconductor layer 106
is away from the light-emitting layer 108, and the second surface
S2 of the bulk portion 106B of the first conductive-type
semiconductor layer 106 is adjacent to the light-emitting layer
108. In addition, the second conductive-type semiconductor layer
110 has a third surface S3 adjacent to the light-emitting layer 108
and a fourth surface S4 away from the light-emitting layer 108. In
some embodiments of the present disclosure, the area of the first
surface S1 is greater than the area of the fourth surface S4. In
addition, the bulk portion 106B, the light-emitting layer 108 and
the second conductive-type semiconductor layer 110 together serve
as a stack structure 112.
[0062] The first conductive-type semiconductor layer 106 has the
first conductive type. The first conductive-type semiconductor
layer 106 may include, but is not limited to, doped
In.sub.xAl.sub.yGa.sub.(1-x-y)N, wherein 0.ltoreq.x.ltoreq.1,
0.ltoreq.y.ltoreq.1 and 0.ltoreq.(x+y).ltoreq.1. For example, in
some embodiments of the present disclosure, the first
conductive-type semiconductor layer 106 may include, but is not
limited to, doped GaN, InN, AlN, In.sub.xGa.sub.(1-x)N,
Al.sub.xIn.sub.(1-x)N, Al.sub.xIn.sub.yGa.sub.(1-x-y)N or any other
suitable materials, wherein 0.ltoreq.x.ltoreq.1,
0.ltoreq.y.ltoreq.1 and 0.ltoreq.(x+y).ltoreq.1. The first
conductive-type semiconductor layer 106 may be a P-type
semiconductor layer, and may be formed by molecular beam epitaxy
(MBE), metalorganic chemical vapor deposition (MOCVD), hydride
vapor phase epitaxy (HVPE), liquid phase epitaxy or any other
suitable epitaxy process.
[0063] The light-emitting layer 108 may include, but is not limited
to, homojunction, heterojunction, single-quantum well (SQW),
multiple-quantum well (MQW) or any other suitable structures. In
some embodiments of the present disclosure, the light-emitting
layer 108 may include undoped N-type In.sub.xGa.sub.(1-x)N. In some
embodiments of the present disclosure, the light-emitting layer 108
may include other materials such as
Al.sub.xIn.sub.yGa.sub.(1-x-y)N. Moreover, the light-emitting layer
108 may include a multiple-quantum well structure with
multiple-quantum layers (such as InGaN) and barrier layers (such as
GaN) arranged alternately. Moreover, the light-emitting layer 108
may be formed by metalorganic chemical vapor deposition (MOCVD),
molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE),
liquid phase epitaxy (LPE) or any other suitable chemical vapor
deposition process. The total thickness of the light-emitting layer
108 may range from about 5 nm to 200 nm.
[0064] The second conductive-type semiconductor layer 110 has the
second conductive type which is different from the first conductive
type. The second conductive-type semiconductor layer 110 may
include, but is not limited to, doped
In.sub.xAl.sub.yGa.sub.(1-x-y)N, wherein 0.ltoreq.x.ltoreq.1,
0.ltoreq.y.ltoreq.1 and 0.ltoreq.(x+y).ltoreq.1. For example, in
some embodiments of the present disclosure, the second
conductive-type semiconductor layer 110 may include, but is not
limited to, doped GaN, InN, AlN, In.sub.xGa.sub.(1-x)N,
Al.sub.xIn.sub.yGa.sub.(1-x-y)N or any other suitable materials,
wherein 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1 and 0
.ltoreq.(x+y).ltoreq.1. The second conductive-type semiconductor
layer 110 may be N-type semiconductor layer, and may be formed by
molecular beam epitaxy (MBE), metalorganic chemical vapor
deposition (MOCVD), hydride vapor phase epitaxy (HVPE), liquid
phase epitaxy or any other suitable epitaxy process.
[0065] In some embodiments of the present disclosure, a
light-emitting material layer and a second conductive-type
semiconductor material may be deposited over a first
conductive-type semiconductor substrate (not shown), then a etching
process is performed to form the substrate portion 106A and the
stack structure 112 disposed over the substrate portion 106A and
having a trapezoidal cross-section, as shown in FIG. 1A. Therefore,
in some embodiments of the present disclosure, the substrate
portion 106A and the bulk portion 106B are formed in one piece.
However, in other embodiments of the present disclosure, the
substrate portion 106A and the bulk portion 106B may not be formed
in one piece.
[0066] In some embodiments of the present disclosure, as shown in
FIG. 1A, the direction perpendicular to the first surface S1 of the
bulk portion 106B is the first direction A1. When viewed from a
cross-sectional view, the acute angle between the sidewall 112S of
the stack structure 112 and the first direction A1 is the angle
.theta., and the angle .theta. ranges from about 1 to 89 degrees,
for example from about 10 to 85 degrees, or from about 20 to 80
degrees, or from about 30 to 75 degrees, or from about 40 to 70
degrees, or from about 50 to 60 degrees, or from about 5 to 50
degrees according to design requirements.
[0067] Still referring to FIG. 1A, the light-emitting diode 104 may
further include a first electrode 114A which is electrically
connected to the first conductive-type semiconductor layer 106. The
light-emitting diode 104 may further include a second electrode
114B which is electrically connected to the second conductive-type
semiconductor layer 110. In some embodiments of the present
disclosure, the first electrode 114A is disposed over the surface
of the substrate portion 106A of the first conductive-type
semiconductor layer 106. The second electrode 114B is disposed over
the fourth surface S4 of the second conductive-type semiconductor
layer 110. In addition, in some embodiments of the present
disclosure, the second electrode 114B completely covers the fourth
surface S4 of the second conductive-type semiconductor layer 110.
In addition, in some embodiments of the present disclosure, the
light-emitting diode 104 is bonded to the substrate 102 with the
second electrode 114B facing toward the substrate 102. In some
embodiments of the present disclosure, the second electrode 114B
may partially cover the fourth surface S4 of the second
conductive-type semiconductor layer 110 according to design
requirements as long as the desired reflection design is
achieved.
[0068] The material of the first electrode 114A and the second
electrode 114B may independently include, but is not limited to, a
single layer or multiple layers of nickel, copper, gold, indium tin
oxide, indium, tin, titanium, a combination thereof, or any other
metal material with good conductivity. In some embodiments of the
present disclosure, the first electrode 114A and the second
electrode 114B may be formed by chemical vapor deposition (CVD),
sputtering, resistive thermal evaporation, electron beam
evaporation, or any other suitable method. The chemical vapor
deposition may include, but is not limited to, low-pressure
chemical vapor deposition (LPCVD), low-temperature chemical vapor
deposition (LTCVD), rapid thermal chemical vapor deposition
(RTCVD), plasma enhanced chemical vapor deposition (PECVD), atomic
layer deposition (ALD), or any other suitable method.
[0069] Still referring to FIG. 1A, the light-emitting diode 104 may
further include a reflection layer 116 disposed over the sidewall
112S of the stack structure 112. In other words, the reflection
layer 116 may be disposed over the sidewall of the first
conductive-type semiconductor layer 106 and the sidewall of the
second conductive-type semiconductor layer 110 respectively. In
other embodiments of the present disclosure, the reflection layer
116 may only be disposed over the sidewall of the bulk portion 106A
of the first conductive-type semiconductor layer 106. As long as
the reflection layer is disposed over at least some regions of the
light-emitting path, the light-emitting shape may be altered or the
light-emitting effectiveness may be improved. The reflection layer
116 may be optionally disposed over the substrate portion 106B of
the first conductive-type semiconductor layer 106. In some
embodiments of the present disclosure, the material of the
reflection layer 116 may include metal and may be the same as or
similar to that of the first electrode 114A and the second
electrode 114B. However, in other embodiments of the present
disclosure, the reflection layer 116 may be a Bragg reflection
layer, and the material of the reflection layer 116 may be
non-metal material or insulating material. For example, in some
embodiments of the present disclosure, the material of the
reflection layer 116 may be the insulating layer with low index of
refraction such as SiO.sub.2 or the insulating layer with high
index of refraction such as SiN. The index of refraction may be
tuned by altering the manufacturing variables or the component
ratio, and the material of the reflection layer 116 is not limited
to the aforementioned materials.
[0070] For example, as shown in FIG. 2A, the reflection layer 116
which serves as the Bragg reflection layer may include a plurality
of sub-reflection layers (for example, the sub-reflection layers
116C1, 116C2 and 116C3). Each of the sub-reflection layers (for
example, the sub-reflection layers 116C1, 116C2 and 116C3) may
sequentially include the reflection layer 116D1 and the reflection
layer 116D2 with different index of refraction. In some embodiments
of the present disclosure, the thicknesses of the reflection layer
116D1 and the reflection layer 116D2 may be less than or equal to
about 0.25 times the optical wavelength (about 1/4 the optical
wavelength). In addition, in other embodiments of the present
disclosure, as shown in FIG. 2B, the reflection layer 116 which
serves as the Bragg reflection layer may include a plurality of
sub-reflection layers (for example, the sub-reflection layers 116C1
and 116C2). Each of the sub-reflection layers (for example, the
sub-reflection layers 116C1 and 116C2) may sequentially include the
reflection layer 116D1, the reflection layer 116D2 and the
reflection layer 116D3 with different index of refraction. In some
embodiments of the present disclosure, the thicknesses of the
reflection layer 116D1, the reflection layer 116D2 and the
reflection layer 116D3 may be less than or equal to about 0.25
times the optical wavelength (about 1/4 the optical
wavelength).
[0071] Still referring to FIG. 1A, in some embodiments of the
present disclosure, the reflection layer 116 is conformally
disposed over the sidewall 112S of the stack structure 112. In
addition, in some embodiments of the present disclosure, the
reflection layer 116 may be in direct contact with the stack
structure 112. However, in other embodiments of the present
disclosure, the reflection layer 116 may not be in direct contact
with the stack structure 112. An insulating layer may be disposed
between the reflection layer 116 and the stack structure 112. The
material of the insulating layer is not limited.
[0072] In addition, in some embodiments of the present disclosure,
as shown in FIG. 1A, the reflection layer 116 does not come into
contact with the second electrode 114B. In other words, in this
embodiment, if the reflection layer 116 is a conductive material,
the reflection layer 116 and the second electrode 114B are
electrically isolated from each other. However, in other
embodiments of the present disclosure, the reflection layer 116 may
be in direct contact with the second electrode 114B.
[0073] In addition, in some embodiments of the present disclosure,
as shown in FIG. 1A, the reflection layer 116A disposed over the
sidewall of the bulk portion 106B of the stack structure 112 is not
electrically connected to the reflection layer 116B disposed over
the sidewall of the second conductive-type semiconductor layer 110.
In other words, in this embodiment, if the reflection layer 116 and
the reflection layer 116B are made of conductive material, the
reflection layer 116A and the reflection layer 116B are
electrically isolated from each other.
[0074] Still referring to FIG. 1A, the width of the first surface
S1 of the bulk portion 106B is width D1, the width of the
light-emitting layer 108 is width D2, the width of the fourth
surface S4 of the second conductive-type semiconductor layer 110 is
the width D3, and the distance from the first surface S1 to the
fourth surface S4 is the distance H1, which is also the thickness
of the stack structure 112. The distance from the first surface S1
to the light-emitting layer 108 is the distance H2, which is also
the height of the light-emitting layer 108 calculated from the
first surface S1. The specific ratio R which includes the width D1,
the width D2, the distance H1 and the distance H2 fit the following
equation 1:
R = ( D 2 .times. H 2 ) ( D 1 .times. H 1 ) . equation 1
##EQU00001##
[0075] Since some embodiments of the present disclosure let the
width D1 of the first surface S1 of the stack structure 112 of the
light-emitting diode 104, the width D2 of the light-emitting layer
108, the distance H1 from the first surface S1 to the fourth
surface S4 (namely the thickness of the stack structure 112), the
distance H2 from the first surface S1 to the light-emitting layer
108 (namely the height of the light-emitting layer 108 calculated
from the first surface S1) has a relationship expressed by equation
1, the light-emitting diode display device of some embodiments of
the present disclosure may freely alter the light-emitting view
angle and the light-emitting shape or may improve the
light-emitting effectiveness. In this embodiment, the reflection
layer 116 is substantially disposed over the entire sidewall of the
stack structure. Since the opening 117 of the reflection layer 116
at the light-emitting direction is the first surface S1, the first
surface S1 substantially coincide with the bottom surface of the
stack structure. In other embodiments of the present disclosure,
the size of the opening at the light-emitting direction is the size
of the bottom surface of the reflection layer, and the opening 117
at the light-emitting direction is referred to as the first surface
S1, therefore, the first surface S1 may not coincide with the
bottom surface of the stack structure. In other words, referring to
FIG. 1B, when the reflection layer 116 does not completely cover
the entire sidewall 112S of the stack structure 112, the first
surface S1 is defined by the datum surface formed by the opening
117 of the reflection layer 116 and may be substantially parallel
to the surface of the substrate portion 106A, but it's not limited
thereto. In this embodiment, the first surface S1 may not coincide
with the bottom surface of the bulk portion 106B.
[0076] In addition, since the additional second lens is not needed
in the embodiments of the present disclosure to alter the
light-emitting view angle and the light-emitting shape, the
embodiments of the present disclosure may lower the cost of the
light-emitting diode display device 100.
[0077] In one embodiment, FIG. 3 is an analytical figure of the
aforementioned specific ratio R versus the half width at half
maximum (HWHM) of the emitted light of the display device 100 in
accordance with some embodiments of the present disclosure. The
line with circle dots shows the relationship between the specific
ratio R versus the half width at half maximum of the emitted light
of the display device 100 when the first surface S1 and the fourth
surface S4 have circular shapes in the top view. The line with
square dots shows the relationship between the specific ratio R
versus the half width at half maximum of the emitted light of the
display device 100 when the first surface S1 and the fourth surface
S4 have square shapes in the top view. In this embodiment, the
specific ratio R may range from about 0.269 to 0.857
(0.269.ltoreq.R.ltoreq.0.857).
[0078] As shown in FIG. 3, when the ratio R is greater than or
equal to 0.269 and is less than 0.3, the half width at half maximum
is greater than or equal to .+-.30.degree. and is less than
.+-.45.degree.. In this embodiment, the light shape is focus shape,
and may be applied to the device which need a straight light such
as an indicator light.
[0079] When the ratio R is greater than or equal to 0.3 and is less
than 0.328, the half width at half maximum is greater than or equal
to .+-.45. In this embodiment, the light shape is focus shape, and
may be applied to a device which needs a straight light such as a
headlight.
[0080] When the ratio R is greater than or equal to 0.328 and is
less than 0.375, the half width at half maximum is greater than
.+-.45.degree. and is less than or equal to .+-.60.degree.. In this
embodiment, the light shape is fan-shape, and may be applied to the
table lamp which need a uniform light. This embodiment may also
solve the issue of non-uniformity of emitted light between two the
light-emitting diodes.
[0081] When the ratio R is greater than or equal to 0.375 and is
less than 0.49, the half width at half maximum is .+-.60.degree. .
In this embodiment, the light shape is between the fan-shape and
Gaussian distribution, and may be applied to the table lamp which
need a uniform light. This embodiment may also solve the issue of
non-uniformity of emitted light between two the light-emitting
diodes.
[0082] When the ratio R is greater than or equal to 0.49 and is
less than 0.857, the half width at half maximum is .+-.50.degree..
In this embodiment, the light shape is a Gaussian distribution, and
may be applied to the package chip such as a surface-mount device
light-emitting diode. For example, this embodiment may be applied
to an edge lighting light source or a bottom-lighting light
source.
[0083] In addition, the first surface S1 of the bulk portion 106B
and the fourth surface S4 of the second conductive-type
semiconductor layer 110 may be any shape. In one embodiment, the
shape of the first surface S1 may substantially have a first axis
and a second axis which are perpendicular to each other. The shape
of the fourth surface S4 may also substantially have a first axis
and a second axis which are perpendicular to each other. Although
the first surface S1 and fourth surface S4 have a first axis and a
second axis, this does not mean that the first surface S1 and
fourth surface S4 need to be completely symmetrical. The first
surface S1 and fourth surface S4 may only have a substantially
corresponding shape. The wires or metal line may be omitted. The
deviation resulted from the manufacture variation may also be
omitted. In some embodiments of the present disclosure, when the
length of the first axis and the length of the second axis are the
same, the first surface S1 and the fourth surface S4 may have a
symmetrical shape. For example, the first surface S1 and the fourth
surface S4 may have a circular shape or a square shape. In other
embodiments of the present disclosure, when the length of the first
axis and the length of the second axis are different, the first
surface S1 and the fourth surface S4 may have a non-symmetrical
shape. For example, the first surface S1 and the fourth surface S4
may have an oval shape or a rectangular shape. In this embodiment,
if the length of the first axis is greater than the length of the
second axis, the first axis may also be referred to as the major
axis, and the second axis may also be referred to as the minor
axis. In addition, in some embodiments of the present disclosure,
the shape of the first surface S1 and the shape of the fourth
surface S4 may be the same. However, in other embodiments of the
present disclosure, the shape of the first surface S1 and the shape
of the fourth surface S4 may be different.
[0084] The relationship between the specific width, the distance,
the ratio of the stack structure and the half width at half maximum
when the first surface S1 and the fourth surface S4 have various
shapes is described as follows. FIG. 4A is a schematic view of the
stack structure 112 in accordance with some embodiments of the
present disclosure. As shown in FIG. 4A, in some embodiments of the
present disclosure, the distance of the first axis D1A of the first
surface S1 is the same as the distance of the second axis D1B of
the first surface S1 (both are the width D1). In addition, the
distance of the first axis D3A of the fourth surface S4 is the same
as the distance of the second axis D3B of the fourth surface S4
(both are the width D3). The first surface S1 and the fourth
surface S4 have a circular shape. The relationship between the
distance H1, the distance H2, the width D1, the width D2, the width
D3, the angle .theta. (for example, the second angle .theta..sub.2
and the first angle .theta..sub.1), the specific ratio R and the
half width at half maximum of the emitted light of the
light-emitting diode 104 and the light-emitting effectiveness is
shown in the following Table 1. In addition, although the first
surface S1 and the fourth surface S4 have a first axis and a second
axis, this does not mean that the first surface S1 and fourth
surface S4 need to be completely symmetrical. The first surface S1
and fourth surface S4 may only have a substantially corresponding
shape. The wires or metal line may be omitted. The deviation
resulted from the manufacture variation may also be omitted. In
table 1, the unit of width and length is um. In addition, in this
embodiment, the stack structure 112 has a first sidewall 112S1 and
a second sidewall 112S2 which are opposite to each other. And the
size of the light-emitting opening of the reflection layer coated
on the first sidewall 112S1 and the second sidewall 112S2 is the
first surface S1. The direction perpendicular to the first surface
S1 and the fourth surface S4 is the direction A1. The acute angle
between the first sidewall 112S1 of the stack structure 112 and the
direction A1 is the first angle .theta..sub.1, the acute angle
between the second sidewall 112S2 of the stack structure 112 and
the direction A1 is the second angle .theta..sub.2. In this
embodiment, as shown in FIG. 4A, the second angle .theta..sub.2 and
the first angle .theta..sub.1 are the same.
TABLE-US-00001 TABLE 1 Light-emitting H1(um) H2(um) D3(um) D1(um)
.theta.1 = .theta.2 D2 (um) R effectiveness HWHM 7 6 1 1 0.degree.
1 0.857 2.95 lm 5.9% 50.degree. 2 4.09.degree. 1.14 0.490 12.23 lm
24.5% 60.degree. 3 8.13.degree. 1.29 0.367 25.55 lm 51.1%
60.degree. 4 12.09.degree. 1.43 0.306 30.20 lm 60.4% 45.degree. 5
15.95.degree. 1.57 0.269 31.63 lm 63.3% 33.degree. 6 5 1 1
0.degree. 1 0.833 3.06 lm 6.1% 50.degree. 2 4.76.degree. 1.17 0.486
12.65 lm 25.3% 60.degree. 3 9.46.degree. 1.33 0.370 25.64 lm 51.3%
60.degree. 4 14.04.degree. 1.50 0.313 29.85 lm 59.7% 45.degree. 5
18.43.degree. 1.67 0.278 31.01 lm .sup. 62% 33.degree. 5 4 1 1
0.degree. 1 0.8 3.17 lm 6.3% 50.degree. 2 5.71.degree. 1.2 0.48
12.98 lm .sup. 26% 60.degree. 3 11.31.degree. 1.4 0.373 25.52 lm
.sup. 51% 60.degree. 4 16.7.degree. 1.6 0.32 29.58 lm 59.2%
45.degree. 5 21.8.degree. 1.8 0.288 30.67 lm 61.3% 40.degree. 4 3 1
1 0.degree. 1 0.75 3.3 lm 6.6% 50.degree. 2 7.13.degree. 1.25 0.469
13.5 lm .sup. 27% 60.degree. 3 14.04.degree. 1.5 0.375 24.96 lm
49.9% 60.degree. 4 20.56.degree. 1.75 0.328 27.64 lm 55.3%
45.degree. 5 26.57.degree. 2 0.3 28.67 lm 57.3% 45.degree. 3 2 1 1
0.degree. 1 0.667 3.44 lm 6.9% 50.degree. 2 9.46.degree. 1.33 0.444
13.93 lm 27.9% 60.degree. 3 18.43.degree. 1.67 0.37 23.81 lm 47.6%
55.degree. 4 26.57.degree. 2 0.333 26.39 lm 52.8% 45.degree. 5
33.69.degree. 2.33 0.311 29.79 lm 59.6% 60.degree.
[0085] In addition, FIG. 4B is an analytical figure of the width D1
of the first surface S1 of the stack structure 112 (or the bottom
surface of the stack structure 112) versus the half width at half
maximum in accordance with this embodiment of the present
disclosure, which corresponds to the data shown in Table 1. In this
embodiment, the ratio R may range from about 0.269 to 0.857
(0.269.ltoreq.R.ltoreq.0.857). In addition, FIG. 4C is a
distribution figure of the emitted light at various view angles in
accordance with this embodiment of the present disclosure when the
ratio R is greater than or equal to 0.269 and is less than 0.3. In
FIG. 4C, the half width at half maximum is .+-.30.degree.. In
addition, FIG. 4D is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the ratio R is greater than or equal to 0.3
and is less than 0.328. In FIG. 4D, the half width at half maximum
is .+-.40.degree.. In addition, FIG. 4E is a distribution figure of
the emitted light at various view angles in accordance with this
embodiment of the present disclosure when the ratio R is greater
than or equal to 0.328 and is less than 0.375. In FIG. 4E, the half
width at half maximum is .+-.60.degree.. In addition, FIG. 4F is a
distribution figure of the emitted light at various view angles in
accordance with this embodiment of the present disclosure when the
ratio R is greater than or equal to 0.375 and is less than 0.49. In
FIG. 4F, the half width at half maximum is .+-.60.degree.. In
addition, FIG. 4G is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the ratio R is greater than or equal to
0.49 and is less than 0.857. In FIG. 4G, the half width at half
maximum is .+-.50.degree.. In addition, in the above figures, the
solid line represents the distribution figure of the emitted light
at various view angles along the direction of the first axis, and
the dash line represents the distribution figure of the emitted
light at various view angles along the direction of the second
axis. Since the length of the first axis is the same as the length
of the second axis in this embodiment, the solid line substantially
overlaps with the dash line.
[0086] Therefore, by tuning the ratio R which ranges from about
0.269 to 0.857, the light-emitting diode display device of some
embodiments of the present disclosure may alter the light-emitting
view angle and the light-emitting shape freely.
[0087] In addition, when the distance H1 is 3 .mu.m, the half width
at half maximum in FIG. 4B increases. This is because the height of
the stack structure 112 becomes too small when the distance H1 is 3
.mu.m, and most light is emitted from the stack structure 112
without being reflected by the sidewall of the stack structure 112.
Since most light is not reflected and focused by reflection by the
sidewall of the stack structure 112, the half width at half maximum
increases. Therefore, the lower limit of the distance H1 in FIG. 4B
is 3 .mu.m.
[0088] FIG. 5A is a schematic view of the stack structure 112 in
accordance with some embodiments of the present disclosure. As
shown in FIG. 5A, in some embodiments of the present disclosure,
the distance of the first axis D1A (also referred to as the major
axis D1A) of the first surface S1 is greater than the distance of
the second axis D1B (also referred to as the minor axis D1B). In
addition, the distance of the first axis D3A (also referred to as
the major axis D3A) of the fourth surface S4 is greater than the
distance of the second axis D3B (also referred to as the minor axis
D3B). The first surface S1 and the fourth surface S4 have an oval
shape. The relationship between the distance H1, the distance H2,
the distance D3A' of the major axis D3A, the distance D3B' of the
minor axis D3B, the distance D1A' of the major axis D1A, the
distance D1B' of the minor axis D1B and the light-emitting
effectiveness of the light-emitting diode 104, the half width at
half maximum A of the emitted light along the direction of the
major axis and the half width at half maximum B of the emitted
light along the direction of the minor axis is shown in the
following Table 2. In addition, although the first surface S1 and
fourth surface S4 have the first axis and the second axis, this
does not mean that the first surface S1 and fourth surface S4 need
to be completely symmetrical. The first surface S1 and fourth
surface S4 may only have a substantially corresponding shape. The
wires or metal line may be omitted. The deviation resulted from the
manufacture variation may also be omitted. In addition, in this
embodiment, the stack structure 112 has a first sidewall 112S1 and
a second sidewall 112S2 which are opposite to each other. And the
size of the light-emitting opening 117 of the reflection layer
coated on the first sidewall 112S1 and the second sidewall 112S2 is
the first surface S1. The direction perpendicular to the first
surface S1 and the fourth surface S4 is the direction A1. The acute
angle between the first sidewall 112S1 of the stack structure 112
and the direction A1 is the first angle .theta..sub.1, the acute
angle between the second sidewall 112S2 of the stack structure 112
and the direction A1 is the second angle .theta..sub.2. In this
embodiment, as shown in FIG. 5A, the second angle .theta..sub.2 and
the first angle .theta..sub.1 are the same.
TABLE-US-00002 TABLE 2 Light-emitting H1(um) H2(um) D3A'(um)
D3B'(um) D1A'(um) D1B'(um) effectiveness HWHM A HWHM B 7 6 1 0.5 1
0.50 2.61 lm 0.052% 35.degree. 35.degree. 2 1.00 10.34 lm 0.207%
50.degree. 50.degree. 3 1.50 22.04 lm 0.441% 55.degree. 60.degree.
4 2.00 27.35 lm 0.547% 45.degree. 48.degree. 5 2.50 29.26 lm 0.585%
38.degree. 35.degree. 6 5 1 0.5 1 0.50 2.78 lm 0.056% 40.degree.
40.degree. 2 1.00 10.85 lm 0.217% 55.degree. 55.degree. 3 1.50
22.49 lm 0.450% 55.degree. 60.degree. 4 2.00 27.38 lm 0.548%
45.degree. 45.degree. 5 2.50 29.13 lm 0.583% 40.degree. 35.degree.
5 4 1 0.5 1 0.50 2.99 lm 0.060% 45.degree. 45.degree. 2 1.00 11.34
lm 0.227% 55.degree. 55.degree. 3 1.50 22.34 lm 0.447% 55.degree.
60.degree. 4 2.00 26.74 lm 0.535% 45.degree. 45.degree. 5 2.50
28.10 lm 0.562% 40.degree. 35.degree. 4 3 1 0.5 1 0.50 3.23 lm
0.065% 50.degree. 50.degree. 2 1.00 11.91 lm 0.238% 60.degree.
60.degree. 3 1.50 21.74 lm 0.435% 55.degree. 60.degree. 4 2.00
25.94 lm 0.519% 50.degree. 45.degree. 5 2.50 26.92 lm 0.538%
45.degree. 40.degree. 3 2 1 0.5 1 0.50 3.58 lm 0.072% 55.degree.
55.degree. 2 1.00 12.31 lm 0.246% 65.degree. 65.degree. 3 1.50
21.18 lm 0.424% 55.degree. 65.degree. 4 2.00 24.46 lm 0.489%
50.degree. 50.degree. 5 2.50 25.25 lm 0.505% 50.degree.
40.degree.
[0089] In addition, FIG. 5B is an analytical figure of the distance
D1A of the major axis of the first surface S1 of the stack
structure 112 (or the bottom surface of the stack structure 112)
versus the half width at half maximum in accordance with this
embodiment of the present disclosure. FIG. 5C is an analytical
figure of the distance D1B of the minor axis of the first surface
S1 of the stack structure 112 (or the bottom surface of the stack
structure 112) versus the half width at half maximum in accordance
with this embodiment of the present disclosure. The results shown
in FIG. 5B and FIG. 5C correspond to the data shown in Table 2.
[0090] Referring to FIGS. 5D-5H, the solid line in FIGS. 5D-5H
represents the distribution figure of the emitted light at various
view angles along the direction of the major axis, and the dash
line in FIGS. 5D-5H represents the distribution figure of the
emitted light at various view angles along the direction of the
minor axis. FIG. 5D is a distribution figure of the emitted light
at various view angles in accordance with this embodiment of the
present disclosure when the distance of the major axis D1A of the
first surface S1 is 1 .mu.m, the distance of the minor axis D1B of
the first surface S1 is 0.5 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0091] In addition, FIG. 5E is a distribution figure of the emitted
light at various view angles in accordance with this embodiment of
the present disclosure when the distance of the major axis D1A of
the first surface S1 is 2 .mu.m, the distance of the minor axis D1B
of the first surface S1 is 1 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0092] FIG. 5F is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the distance of the major axis D1A of the
first surface S1 is 3 .mu.m, the distance of the minor axis D1B of
the first surface S1 is 1.5 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0093] FIG. 5G is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the distance of the major axis D1A of the
first surface S1 is 4 .mu.m, the distance of the minor axis D1B of
the first surface S1 is 2 .mu.m, the distance of the major axis D3A
of the fourth surface S4 is 1 .mu.m, the distance of the minor axis
D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is 7
.mu.m and the distance H2 is 6 .mu.m.
[0094] FIG. 5H is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the distance of the major axis D1A of the
first surface S1 is 5 .mu.m, the distance of the minor axis D1B of
the first surface S1 is 2.5 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0095] Therefore, by tuning the distance of the major axis of the
first surface and the distance of the minor axis of the first
surface, the light-emitting diode display device of some
embodiments of the present disclosure may alter the light-emitting
view angle and the light-emitting shape freely.
[0096] FIG. 6A is a schematic view of the stack structure 112 in
accordance with some embodiments of the present disclosure. As
shown in FIG. 6A, in some embodiments of the present disclosure,
the distance of the first axis D1A of the first surface S1 is the
same as the distance of the second axis D1B of the first surface S1
(both are the width D1). In addition, the distance of the first
axis D3A of the fourth surface S4 is the same as the distance of
the second axis D3B of the fourth surface S4 (both are the width
D3). The first surface S1 and the fourth surface S4 have a square
shape. The relationship between the distance H1, the distance H2,
the width D1, the width D2, the width D3, the angle .theta. (for
example, the second angle .theta..sub.2 and the first angle
.theta..sub.1), the specific ratio R and the half width at half
maximum of the emitted light of the light-emitting diode 104 and
the light-emitting effectiveness is shown in the following Table 3.
In addition, although the first surface S1 and fourth surface S4
have a first axis and a second axis, this does not mean that the
first surface S1 and fourth surface S4 need to be completely
symmetrical. The first surface S1 and fourth surface S4 may only
have a substantially corresponding shape. The wires or metal line
may be omitted. The deviation resulted from the manufacture
variation may also be omitted. In addition, in this embodiment, the
stack structure 112 has a first sidewall 112S1 and a second
sidewall 112S2 which are opposite to each other. And the size of
the light-emitting opening 117 of the reflection layer coated on
the first sidewall 112S1 and the second sidewall 112S2 is the first
surface S1. The direction perpendicular to the first surface S1 and
the fourth surface S4 is the direction A1. The acute angle between
the first sidewall 112S1 of the stack structure 112 and the
direction A1 is the first angle .theta..sub.1, the acute angle
between the second sidewall 112S2 of the stack structure 112 and
the direction A1 is the second angle .theta..sub.2. In this
embodiment, as shown in FIG. 6A, the second angle .theta..sub.2 and
the first angle .theta..sub.1 are the same.
TABLE-US-00003 TABLE 3 Light-emitting H1(um) H2(um) D3(um) D1(um)
.theta.1 = .theta.2 D2 (um) R effectiveness HWHM 7 6 1 1
0.00.degree. 1.00 0.857 2.94 lm 5.87% 50.degree. 2 4.09.degree.
1.14 0.490 12.17 lm 24.35% 60.degree. 3 8.13.degree. 1.29 0.367
24.59 lm 49.17% 60.degree. 4 12.09.degree. 1.43 0.306 28.43 lm
56.87% 45.degree. 5 15.95.degree. 1.57 0.269 29.41 lm 58.82%
35.degree. 6 5 1 1 0.00.degree. 1.00 0.833 3.04 lm 6.08% 50.degree.
2 4.76.degree. 1.17 0.486 12.62 lm 25.24% 60.degree. 3 9.46.degree.
1.33 0.370 24.46 lm 48.92% 60.degree. 4 14.04.degree. 1.50 0.313
27.72 lm 55.45% 45.degree. 5 18.43.degree. 1.67 0.278 28.40 lm
56.80% 35.degree. 5 4 1 1 0.00.degree. 1.00 0.800 3.17 lm 6.34%
50.degree. 2 5.71.degree. 1.20 0.480 12.95 lm 25.90% 60.degree. 3
11.31.degree. 1.40 0.373 24.02 lm 48.03% 60.degree. 4 16.70.degree.
1.60 0.320 26.96 lm 53.91% 45.degree. 5 21.80.degree. 1.80 0.288
27.14 lm 54.27% 40.degree. 4 3 1 1 0.00.degree. 1.00 0.750 3.29 lm
6.58% 50.degree. 2 7.13.degree. 1.25 0.469 13.54 lm 27.08%
60.degree. 3 14.04.degree. 1.50 0.375 23.18 lm 46.36% 60.degree. 4
20.56.degree. 1.75 0.328 25.34 lm 50.67% 45.degree. 5 26.57.degree.
2.00 0.300 25.18 lm 50.36% 45.degree. 3 2 1 1 0.00.degree. 1.00
0.667 3.44 lm 6.88% 50.degree. 2 9.46.degree. 1.33 0.444 13.78 lm
27.57% 60.degree. 3 18.43.degree. 1.67 0.370 22.38 lm 44.77%
50.degree. 4 26.57.degree. 2.00 0.333 23.92 lm 47.83% 50.degree. 5
33.69.degree. 2.33 0.311 27.81 lm 55.61% 60.degree.
[0097] In addition, FIG. 6B is an analytical figure of the width D1
of the first surface S1 of the stack structure 112 (or the bottom
surface of the stack structure 112) versus the half width at half
maximum in accordance with this embodiment of the present
disclosure, which corresponds to the data shown in Table 3. In this
embodiment, the ratio R may range from about 0.269 to 0.857
(0.269.ltoreq.R.ltoreq.0.857). In addition, FIG. 6C is a
distribution figure of the emitted light at various view angles in
accordance with this embodiment of the present disclosure when the
ratio R is greater than or equal to 0.269 and is less than 0.3. In
FIG. 6C, the half width at half maximum is .+-.30.degree.. In
addition, FIG. 6D is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the ratio R is greater than or equal to 0.3
and is less than 0.328. In FIG. 6D, the half width at half maximum
is .+-.40.degree.. In addition, FIG. 6E is a distribution figure of
the emitted light at various view angles in accordance with this
embodiment of the present disclosure when the ratio R is greater
than or equal to 0.328 and is less than 0.375. In FIG. 6E, the half
width at half maximum is .+-.60.degree.. In addition, FIG. 6F is a
distribution figure of the emitted light at various view angles in
accordance with this embodiment of the present disclosure when the
ratio R is greater than or equal to 0.375 and is less than 0.49. In
FIG. 6F, the half width at half maximum is .+-.60.degree.. In
addition, FIG. 6G is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the ratio R is greater than or equal to
0.49 and is less than 0.857. In FIG. 6G, the half width at half
maximum is .+-.50.degree..
[0098] In addition, in the above figures, the solid line represents
the distribution figure of the emitted light at various view angles
along the direction of the first axis, and the dash line represents
the distribution figure of the emitted light at various view angles
along the direction of the second axis. Since the length of the
first axis is the same as the length of the second axis in this
embodiment, the solid line substantially overlaps with the dash
line.
[0099] Therefore, by tuning the ratio R which ranges from about
0.269 to 0.857, the light-emitting diode display device of some
embodiments of the present disclosure may alter the light-emitting
view angle and the light-emitting shape freely.
[0100] FIG. 7A is a schematic view of the stack structure 112 in
accordance with some embodiments of the present disclosure. As
shown in FIG. 7A, in some embodiments of the present disclosure,
the distance of the first axis D1A (also referred to as the major
axis D1A) of the first surface S1 is greater than the distance of
the second axis D1B (also referred to as the minor axis D1B). In
addition, the distance of the first axis D3A (also referred to as
the major axis D3A) of the fourth surface S4 is greater than the
distance of the second axis D3B (also referred to as the minor axis
D3B). The first surface S1 and the fourth surface S4 have a
rectangular shape. The relationship between the distance H1, the
distance H2, the distance D3A' of the major axis D3A, the distance
D3B' of the minor axis D3B, the distance D1A' of the major axis
D1A, the distance D1B' of the minor axis D1B and the light-emitting
effectiveness of the light-emitting diode 104, the half width at
half maximum A of the emitted light along the direction of the
major axis and the half width at half maximum B of the emitted
light along the direction of the minor axis is shown in the
following Table 4. In addition, although the first surface S1 and
fourth surface S4 have the first axis and the second axis, this
does not mean that the first surface S1 and fourth surface S4 need
to be completely symmetrical. The first surface S1 and fourth
surface S4 may only have a substantially corresponding shape. The
wires or metal line may be omitted. The deviation resulted from the
manufacture variation may also be omitted. In addition, in this
embodiment, the stack structure 112 has a first sidewall 112S1 and
a second sidewall 112S2 which are opposite to each other. And the
size of the light-emitting opening 117 of the reflection layer
coated on the first sidewall 112S1 and the second sidewall 112S2 is
the first surface S1. The direction perpendicular to the first
surface S1 and the fourth surface S4 is the direction A1. The acute
angle between the first sidewall 112S1 of the stack structure 112
and the direction A1 is the first angle .theta..sub.1, the acute
angle between the second sidewall 112S2 of the stack structure 112
and the direction A1 is the second angle .theta..sub.2. In this
embodiment, as shown in FIG. 7A, the second angle .theta..sub.2 and
the first angle .theta..sub.1 are the same.
TABLE-US-00004 TABLE 4 Light-emitting H1(um) H2(um) D3A'(um)
D3B'(um) D1A'(um) D1B'(um) effectiveness HWHM A HWHM B 7 6 1 0.5 1
0.50 2.60 lm 5.20% 50.degree. 40.degree. 2 1.00 10.36 lm 20.72%
60.degree. 50.degree. 3 1.50 22.05 lm 44.11% 58.degree. 58.degree.
4 2.00 26.78 lm 53.56% 45.degree. 45.degree. 5 2.50 28.70 lm 57.40%
35.degree. 30.degree. 6 5 1 0.5 1 0.50 2.74 lm 5.49% 50.degree.
45.degree. 2 1.00 10.80 lm 21.60% 60.degree. 50.degree. 3 1.50
22.31 lm 44.62% 60.degree. 60.degree. 4 2.00 26.65 lm 53.31%
45.degree. 45.degree. 5 2.50 28.22 lm 56.44% 35.degree. 35.degree.
5 4 1 0.5 1 0.50 2.89 lm 5.79% 50.degree. 40.degree. 2 1.00 11.21
lm 22.42% 60.degree. 50.degree. 3 1.50 22.19 lm 44.38% 60.degree.
60.degree. 4 2.00 26.30 lm 52.59% 45.degree. 45.degree. 5 2.50
27.47 lm 54.95% 45.degree. 35.degree. 4 3 1 0.5 1 0.50 3.05 lm
6.11% 60.degree. 45.degree. 2 1.00 11.69 lm 23.37% 60.degree.
50.degree. 3 1.50 21.59 lm 43.17% 60.degree. 60.degree. 4 2.00
25.21 lm 50.42% 45.degree. 45.degree. 5 2.50 25.70 lm 51.40%
45.degree. 40.degree. 3 2 1 0.5 1 0.50 3.24 lm 6.48% 55.degree.
50.degree. 2 1.00 11.98 lm 23.97% 60.degree. 65.degree. 3 1.50
20.83 lm 41.66% 50.degree. 60.degree. 4 2.00 23.52 lm 47.04%
50.degree. 50.degree. 5 2.50 25.78 lm 51.56% 60.degree.
45.degree.
[0101] In addition, FIG. 7B is an analytical figure of the distance
D1A of the major axis of the first surface S1 of the stack
structure 112 (or the bottom surface of the stack structure 112)
versus the half width at half maximum in accordance with this
embodiment of the present disclosure. FIG. 7C is an analytical
figure of the distance D1B of the minor axis of the first surface
S1 of the stack structure 112 (or the bottom surface of the stack
structure 112) versus the half width at half maximum in accordance
with this embodiment of the present disclosure. The results shown
in FIG. 7B and FIG. 7C correspond to the data shown in Table 4.
[0102] FIG. 7D is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the distance of the major axis D1A of the
first surface S1 is 1 .mu.m, the distance of the minor axis D1B of
the first surface S1 is 0.5 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0103] In addition, FIG. 7E is a distribution figure of the emitted
light at various view angles in accordance with this embodiment of
the present disclosure when the distance of the major axis D1A of
the first surface S1 is 2 .mu.m, the distance of the minor axis D1B
of the first surface S1 is 1 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0104] In addition, FIG. 7F is a distribution figure of the emitted
light at various view angles in accordance with this embodiment of
the present disclosure when the distance of the major axis D1A of
the first surface S1 is 3 .mu.m, the distance of the minor axis D1B
of the first surface S1 is 1.5 .mu.m, the distance of the major
axis D3A of the fourth surface S4 is 1 .mu.m, the distance of the
minor axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance
H1 is 7 .mu.m and the distance H2 is 6 .mu.m.
[0105] In addition, FIG. 7G is a distribution figure of the emitted
light at various view angles in accordance with this embodiment of
the present disclosure when the distance of the major axis D1A of
the first surface S1 is 4 .mu.m, the distance of the minor axis D1B
of the first surface S1 is 2 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0106] FIG. 7H is a distribution figure of the emitted light at
various view angles in accordance with this embodiment of the
present disclosure when the distance of the major axis D1A of the
first surface S1 is 5 .mu.m, the distance of the minor axis D1B of
the first surface S1 is 2.5 .mu.m, the distance of the major axis
D3A of the fourth surface S4 is 1 .mu.m, the distance of the minor
axis D3B of the fourth surface S4 is 0.5 .mu.m, the distance H1 is
7 .mu.m and the distance H2 is 6 .mu.m.
[0107] In addition, the solid line in FIGS. 5D-5H represents the
distribution figure of the emitted light at various view angles
along the direction of the major axis, and the dash line in FIGS.
5D-5H represents the distribution figure of the emitted light at
various view angles along the direction of the minor axis.
[0108] Therefore, by tuning the distance of the major axis of the
first surface and the distance of the minor axis of the first
surface, the light-emitting diode display device of some
embodiments of the present disclosure may alter the light-emitting
view angle and the light-emitting shape freely.
[0109] FIG. 8A is a cross-sectional view of the stack structure 112
in accordance with some embodiments of the present disclosure. The
light L is the light emitted from the light-emitting layer 108. The
direction perpendicular to the first surface S1 and the fourth
surface S4 is the direction A1, and the direction perpendicular to
the first sidewall 112S1 of the stack structure 112 is the
direction A2. The shape of the first surface S1 and the fourth
surface S4 when viewed from a top view may be the shape shown in
FIGS. 4A, 5A, 6A, 7A or any other suitable shape. In addition, in
this embodiment, the size of the light-emitting opening 117 of the
reflection layer coated on the first sidewall 112S1 and the second
sidewall 112S2 is the first surface S1.
[0110] In the stack structure 112, the acute angle between the
light L just emitted from the light-emitting layer 108 and the
direction A1 at the light-emitting layer 108 is .theta..sub.e, the
acute angle between the light L and the direction A2 at the first
sidewall 112S1 is .theta..sub.r, the acute angle between the light
L reflected by the sidewall 112S1 of the stack structure 112 and
the direction A1 at the first surface S1 is .theta..sub.i. In
addition, the acute angle between the light L emitted from the
stack structure 112 and the direction A1 at the first surface S1 is
.theta..sub.o. Since the thickness of the light-emitting layer is
thinner than that of other layers, the thickness of the
light-emitting layer is omitted in the embodiments of the present
disclosure.
[0111] In addition, when viewed from a cross-sectional view, the
acute angle between the direction A1 and the first sidewall 112S1
of the stack structure 112 is the first angle .theta..sub.1. The
first angle .theta..sub.1 may range from about 1 to 89 degrees. In
addition, the stack structure 112 may further include the second
sidewall 112S2, and the first sidewall 112S1 and the second
sidewall 112S2 are opposite to each other. The acute angle between
the direction A1 and the second sidewall 112S2 of the stack
structure 112 is the second angle .theta..sub.2. In this
embodiment, as shown in FIG. 8A, the second angle .theta..sub.2 is
the same as the first angle .theta..sub.1.
[0112] As shown in FIG. 8A, the angle .theta..sub.r is equals
90.degree. minus the angle .theta..sub.e and plus the first angle
.theta..sub.1
(.theta..sub.r=(90.degree.-.theta..sub.c)+.theta..sub.1), and the
angle .theta..sub.i equals to 90.degree. minus the angle
.theta..sub.r and plus the first angle .theta..sub.1
(.theta..sub.i=90.degree.-(.theta..sub.r+.theta..sub.1)).
Therefore, the angle .theta..sub.i equals the angle .theta..sub.e
minus two times the first angle .theta..sub.1
(.theta..sub.i=.theta..sub.e-(2.times..theta..sub.1)). If the light
L is emitted from the stack structure 112 after n times
reflections, the angle .theta..sub.i equals the angle .theta..sub.e
minus 2n times the first angle
.theta..sub.1(.theta..sub.i=.theta..sub.e-(2n.times..theta..sub.1))-
.
[0113] In addition, according to Snell' s Law, when nl is the index
of refraction of the bulk portion 106B (or the first
conductive-type semiconductor layer 106) and n2 is the index of
refraction of the medium that the light L is located at after being
emitted from the stack structure 112 (or the bulk portion 106B),
the angle .theta..sub.o, the angle .theta..sub.i, the index of
refraction n1 and the index of refraction n2 have a relationship
expressed by the following equation 2:
.theta. o = sin - 1 n 1 .times. sin .theta. i n 2 . equation 2
##EQU00002##
[0114] In some embodiments of the present disclosure, the material
of the first conductive-type semiconductor layer 106 is GaN, and
the index of refraction n1 is 2.38. The medium that the light L is
located at after being emitted from the stack structure 112 (or the
bulk portion 106B) is air and the index of refraction n2 is 1.
[0115] FIG. 8B is a cross-sectional view of the stack structure 112
in accordance with some embodiments of the present disclosure. In
this embodiment, the size of the light-emitting opening of the
reflection layer coated on the first sidewall 112S1 and the second
sidewall 112S2 is the first surface S1. The shape of the first
surface S1 and the fourth surface S4 when viewed from a top view
may be the shape shown in FIGS. 4A, 5A, 6A, 7A or any other
suitable shape. As shown in FIG. 8B, the second angle .theta..sub.2
is different from the first angle .theta..sub.1. In addition, when
viewed from a cross-sectional view, the extension line of the
fourth surface S4 is the extension line S4E, the extension line of
the first sidewall 112S1 is the extension line 112S1E, the
extension line of the second sidewall 112S2 is the extension line
112S2E. The intersection point of the extension line S4E and the
extension line 112S1E is the point A, the intersection point of the
extension line S4E and the extension line 112S2E is the point D,
the intersection point of the first surface S1 and the extension
line 112S1E is the point B, the intersection point of the first
surface S1 and the extension line 112S2E is the point C. In other
words, the point B and the point C are two end points of the
reflection layer on the first sidewall 112S1 and the second
sidewall 112S2. Two end points of the light-emitting layer 108
(shown by dash line in FIG. 8B in order to clearly describe the
embodiments of the present disclosure) are the point E and the
point F. In addition, the projected point of the point A along the
direction A1 on the light-emitting layer 108 is the point G, the
projected point of the point A along the direction A1 on the first
surface S1 is the point G', the projected point of the point D
along the direction A1 on the light-emitting layer 108 is the point
H, the projected point of the point D along the direction A1 on the
first surface S1 is the point H'. In addition, the intersection
point of the first surface S1 and the line which is parallel to the
line DC and penetrates through the point A is the point Q. In other
words, the line AQ is parallel to the line DC. In addition, the
intersection of the line AQ and the light-emitting layer 108 (or
the line EF) is the point P. Since the thickness of the
light-emitting layer is thinner than that of other layers, the
thickness of the light-emitting layer is omitted in the embodiments
of the present disclosure.
[0116] According to FIG. 8B, the ratio of the length of the line AE
to the length of the line AB equals the ratio of the length of the
line EP to the length of the line BQ (the length of the line AE:
the length of the line AB=the length of the line EP: the length of
the line BQ). The length of the line AD is the width D3, the length
of the line BC is the width D1. Accordingly, the ratio of the value
derived by minus the distance H1 by the distance H2 to the distance
H1 is equal to the ratio of the length of the line EP to the value
derived by minus the width D1 by the width D3 ((H1-H2): H1=(the
length of the line EP): (D1-D3)). Accordingly, the length of the
line EP may be represented by the following equation 3:
EP _ = ( H 1 - H 2 ) .times. ( D 1 - D 3 ) H 1 . equation 3
##EQU00003##
[0117] In addition, according to FIG. 8B, the length of the line PF
is the width D3, and the width D2 of the light-emitting layer 108
equals the length of the line EP plus the length of the line PF. In
other words, the width D2 of the light-emitting layer 108 may be
represented by the following equation 4:
D 2 = ( H 1 - H 2 ) .times. ( D 1 - D 3 ) H 1 + D 3. equation 4
##EQU00004##
[0118] In addition, according to FIG. 8B, the width D2 of the
light-emitting layer 108 may also be represented by the following
equation 5:
D2=D3+[(H1-H2).times.(tan .theta.1-tan .theta.2) equation 5.
[0119] It should be noted that, although the above equations 4 and
5 are used to represent the width D2 of the light-emitting layer
108 of the stack structure 112 shown in FIG. 8B in which the second
angle .theta..sub.2 is different from the first angle
.theta..sub.1, the equations 4 and 5 may also be used to represent
the width D2 of the light-emitting layer 108 of the stack structure
112 shown in FIG. 8A in which the second angle .theta..sub.2 is the
same as the first angle .theta..sub.1.
[0120] FIG. 9A is a cross-sectional view of a light-emitting diode
104A of a display device 200 in accordance with some other
embodiments of the present disclosure. Note that the same or
similar elements or layers corresponding to those of the
semiconductor device are denoted by like reference numerals. The
same or similar elements or layers denoted by like reference
numerals have the same meaning and will not be repeated for the
sake of brevity.
[0121] The difference between the embodiment shown in FIG. 9A and
the embodiment shown in FIG. 1A is that the reflection layer 116
may include a plurality of sub-reflection layers 116E which are not
electrically connected to each other. The plurality of
sub-reflection layers 116E surrounds the stack structure 112. In
addition, in some embodiments of the present disclosure, as shown
in FIG. 9A, the reflection layer 116 may be in direct contact with
the second electrode 114B. In addition, in some embodiments of the
present disclosure, as shown in FIG. 9A, the sub-reflection layers
116E disposed over the sidewall 112S of the bulk portion 106B of
the stack structure 112 are not electrically connected to the
sub-reflection layers 116E disposed over the sidewall of the second
conductive-type semiconductor layer 110. In this embodiment, the
reflection layer 116 is substantially disposed over the entire
sidewall 112S of the stack structure 112. Therefore, the size of
the opening 117 along the light-emitting direction is the first
surface S1, and the first surface S1 is overlapped with the bottom
surface of the stack structure 112. The shape of the first surface
S1 and the fourth surface S4 when viewed from a top view may be the
shape shown in FIGS. 4A, 5A, 6A, 7A or any other suitable
shape.
[0122] In other embodiments of the present disclosure, the size of
the opening 117 along the light-emitting direction is the size of
the bottom surface of the reflection layer 116 adjacent to the
bottom surface of the stack structure 112. The size of the opening
117 along the light-emitting direction is the first surface S1, and
the first surface S1 does not overlap with the bottom surface of
the stack structure 112. In other words, similar to the embodiment
shown in FIG. 1B, when the reflection layer 116 does not completely
cover the entire sidewall 112S of the stack structure 112, the
first surface S1 is defined by the datum surface formed by the
opening 117 of the reflection layer 116 and is substantially
parallel to the surface of the substrate portion 106A. In this
embodiment, the first surface S1 may not coincide with the bottom
surface of the bulk portion 106B.
[0123] FIG. 9B is a cross-sectional view of a light-emitting diode
104B of a display device 300 in accordance with some other
embodiments of the present disclosure. The difference between the
embodiment shown in FIG. 9B and the embodiment shown in FIG. 9A is
that the reflection layer 116 has a thickness which is gradually
changed. In one embodiment, in some embodiments of the present
disclosure, the thickness of the reflection layer 116 increases
from the first surface S1 to the fourth surface S4. In addition, in
some embodiments of the present disclosure, the portion of the
reflection layer 116 corresponding to the light-emitting layer 108
may be broken off or spaced apart and may have a spacing 122. The
spacing 122 may not be filled by any material or may be filled by
an insulating layer. In addition, in this embodiment, the
reflection layer 116 is substantially disposed over the entire
sidewall 112S of the stack structure 112. Since the opening in the
light-emitting direction is the first surface S1, the first surface
S1 is overlapped with the bottom surface of the stack structure
112. The shape of the first surface S1 and the fourth surface S4
when viewed from a top view may be the shape shown in FIGS. 4A, 5A,
6A, 7A or any other suitable shape. In other embodiments of the
present disclosure, the size of the opening along the
light-emitting direction is the size of the bottom surface of the
reflection layer 116 adjacent to the bottom surface of the stack
structure 112. The size of the opening along the light-emitting
direction is the first surface S1, and the first surface S1 does
not overlap with the bottom surface of the stack structure 112. In
other words, similar to the embodiment shown in FIG. 1B, when the
reflection layer 116 does not completely cover the entire sidewall
112S of the stack structure 112, the first surface S1 is defined by
the datum surface formed by the opening of the reflection layer 116
and is substantially parallel to the surface of the substrate
portion 106A. In this embodiment, the first surface S1 may not
coincide with the bottom surface of the bulk portion 106B.
[0124] In addition, in some embodiments of the present disclosure,
the sidewall 116S1 of the reflection layer 116 may be perpendicular
to the first surface S1, and the surface 116S2 of the reflection
layer 116 has a height that is the same as that of the fourth
surface S4.
[0125] In some embodiments of the present disclosure, a reflection
layer 116 with a thickness which is gradually changed may be formed
by the following steps. First, a patterned mask is formed, exposing
the region which is predetermined to form the reflection layer 116.
Subsequently, the material of the reflection layer is deposited to
form the reflection layer 116.
[0126] FIG. 9C is a cross-sectional view of a light-emitting diode
104C of a display device 400 in accordance with some other
embodiments of the present disclosure. The difference between the
embodiment shown in FIG. 9C and the embodiment shown in FIG. 9B is
that the first conductive-type semiconductor layer 106 may further
include a plurality of pillar portions 106C disposed over the
substrate portion 106A. In addition, there is a recess 118 formed
by two adjacent pillar portions 106C of the plurality of pillar
portions 106C and the substrate portion 106A. In addition, the bulk
portion 106B is disposed in the recess 118. In addition, in this
embodiment, the reflection layer 116 is substantially disposed over
the entire sidewall 112S of the stack structure 112. Since the
opening at the light-emitting direction is the first surface S1,
the first surface S1 is overlapped with the bottom surface of the
stack structure 112. The shape of the first surface S1 and the
fourth surface S4 when viewed from a top view may be the shape
shown in FIGS. 4A, 5A, 6A, 7A or any other suitable shape. The
shapes of the first surface S1 and the fourth surface S4 in
different stack structures 112 may be different. In other
embodiments of the present disclosure, the size of the opening 117
along the light-emitting direction is the size of the bottom
surface of the reflection layer 116 adjacent to the bottom surface
of the stack structure 112. The size of the opening along the
light-emitting direction is the first surface S1, and the first
surface S1 does not overlap with the bottom surface of the stack
structure 112. In other words, similar to the embodiment shown in
FIG. 1B, when the reflection layer 116 does not completely cover
the entire sidewall 112S of the stack structure 112, the first
surface S1 is defined by the datum surface formed by the opening
117 of the reflection layer 116 and is substantially parallel to
the surface of the substrate portion 106A. In this embodiment, the
first surface S1 may not coincide with the bottom surface of the
bulk portion 106B.
[0127] In addition, in some embodiments of the present disclosure,
a spacing 120 is disposed between the bulk portion 106B and the
sidewall 118S of the recess 118. The reflection layer 116 is
disposed in the spacing 120, as shown in FIG. 9C. In other
embodiments of the present disclosure, the spacing 120 is not
completely filled by the reflection layer. The spacing 120 may only
be partially filled by the reflection layer. As long as the design
of the reflection layer may achieve the effect of altering the
light shape or improving the light-emitting effectiveness.
[0128] In addition, in some embodiments of the present disclosure,
the portion of the reflection layer 116 corresponding to the
light-emitting layer 108 may be broken off or spaced apart and may
have a spacing 122. The spacing 122 may not be filled by any
material or may be filled by an insulating layer.
[0129] In some embodiments of the present disclosure, the
light-emitting diode 104C in FIG. 9C may be formed by the following
steps. First, the light-emitting diode in FIG. 9B is formed. But
the first electrode and the second electrode are not formed yet.
Subsequently, a first conductive type material is deposited to form
a plurality of pillar portions 106C. Subsequently, the first
electrode 114A, the second electrode 114B and the reflection layer
116 are formed, and the first electrode 114A is formed over the
pillar portions 106C. However, in other embodiments of the present
disclosure, one or a plurality of etching and deposition steps
(used to deposit the light-emitting layer 108, the second
conductive-type semiconductor layer 110 and /or the bulk portion
106B) may be performed on a first conductive-type semiconductor
substrate (not shown) to form spacing 120, the stack structure 112
and the plurality of pillar portions 106C. However, it should be
noted that the embodiments of the present disclosure is not limited
thereto. The light-emitting diode 104C in FIG. 9C may be formed by
any other suitable manufacturing method. In addition, in some
embodiments of the present disclosure, the substrate portion 106A,
the bulk portion 106B and the pillar portions 106C of the first
conductive-type semiconductor layer 106 may be formed in one piece.
However, in other embodiments of the present disclosure, the
substrate portion 106A and the bulk portion 106B are formed in one
piece, whereas the substrate portion 106A and the pillar portions
106C are not formed in one piece.
[0130] In summary, in some embodiments of the present disclosure,
since the specific width and distance in the stack structure of the
light-emitting diode have a specific relationship, the
light-emitting diode display device in some embodiments of the
present disclosure may alter the light-emitting view angle and the
light-emitting shape freely. In addition, an additional second lens
is not needed in the embodiments of the present disclosure to alter
the light-emitting view angle and the light-emitting shape.
[0131] Note that the above element sizes, element parameters, and
element shapes are not limitations of the present disclosure. Those
skilled in the art can adjust these settings or values according to
different requirements. It should be understood that the display
device and method for manufacturing the same of the present
disclosure are not limited to the configurations of FIGS. 1 to 9C.
The present disclosure may merely include any one or more features
of any one or more embodiments of FIGS. 1 to 9C. In other words,
not all of the features shown in the figures should be implemented
in the display device and method for manufacturing the same of the
present disclosure.
[0132] In addition, in some embodiments of the present disclosure,
the reflection layer may only be disposed over the sidewall of the
bulk portion of the first conductive-type semiconductor layer. The
reflection layer 116 may be optionally disposed over the substrate
portion of the first conductive-type semiconductor layer. As long
as the reflection layer is disposed over at least some regions of
the light-emitting path, the light-emitting shape may be altered or
the light-emitting effectiveness may be improved.
[0133] Although some embodiments of the present disclosure and
their advantages have been described in detail, it should be
understood that various changes, substitutions and alterations can
be made herein without departing from the spirit and scope of the
disclosure as defined by the appended claims. For example, it will
be readily understood by those skilled in the art that many of the
features, functions, processes, and materials described herein may
be varied while remaining within the scope of the present
disclosure. Moreover, the scope of the present application is not
intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and operations described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure of the present disclosure, processes, machines,
manufacture, compositions of matter, means, methods, or operations,
presently existing or later to be developed, that perform
substantially the same function or achieve substantially the same
result as the corresponding embodiments described herein may be
utilized according to the present disclosure. Accordingly, the
appended claims are intended to include within their scope such
processes, machines, manufacture, compositions of matter, means,
methods, or operations.
* * * * *