U.S. patent application number 15/535986 was filed with the patent office on 2018-01-11 for optical filter and manufacturing method therefor, display substrate, and display apparatus.
The applicant listed for this patent is BOE TECHNOLOGY GROUP CO., LTD., HEFEI XINSHENG OPTOELECTRONICS TECHNOLOGY CO., LTD.. Invention is credited to Lei GUO, Liangliang JIANG, Haifeng WANG, Yong Jun YOON.
Application Number | 20180011231 15/535986 |
Document ID | / |
Family ID | 54951878 |
Filed Date | 2018-01-11 |
United States Patent
Application |
20180011231 |
Kind Code |
A1 |
JIANG; Liangliang ; et
al. |
January 11, 2018 |
OPTICAL FILTER AND MANUFACTURING METHOD THEREFOR, DISPLAY
SUBSTRATE, AND DISPLAY APPARATUS
Abstract
An optical filter and manufacturing method therefor, a display
substrate, and a display apparatus. The optical filter includes: a
base substrate; an ordered porous film disposed on the base
substrate, wherein the ordered porous film is formed with channels
each of which having an extension direction at least at an angle to
the base substrate and having an opening at a surface of the
ordered porous film; and a plurality of quantum dots respectively
disposed in at least part of the channels. The optical filter, the
display substrate having the optical filter and the display
apparatus can significantly improve the display colour gamut of the
display apparatus.
Inventors: |
JIANG; Liangliang; (Beijing,
CN) ; WANG; Haifeng; (Beijing, CN) ; GUO;
Lei; (Beijing, CN) ; YOON; Yong Jun; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOE TECHNOLOGY GROUP CO., LTD.
HEFEI XINSHENG OPTOELECTRONICS TECHNOLOGY CO., LTD. |
Beijing
Hefei City, Anhui |
|
CN
CN |
|
|
Family ID: |
54951878 |
Appl. No.: |
15/535986 |
Filed: |
September 30, 2016 |
PCT Filed: |
September 30, 2016 |
PCT NO: |
PCT/CN2016/101142 |
371 Date: |
June 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 1/1335 20130101;
G02F 1/133514 20130101; G02F 2202/36 20130101; G02F 1/133617
20130101; B82Y 20/00 20130101; G02B 5/201 20130101; H05B 33/145
20130101; G02B 5/223 20130101 |
International
Class: |
G02B 5/20 20060101
G02B005/20; G02F 1/1335 20060101 G02F001/1335; G02B 5/22 20060101
G02B005/22; H05B 33/14 20060101 H05B033/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 30, 2015 |
CN |
201510728954.9 |
Claims
1. An optical filter comprising: a base substrate; an ordered
porous film disposed on the base substrate, wherein the ordered
porous film is formed with channels each of which having an
extension direction at least at an angle to the base substrate and
having an opening at a surface of the ordered porous film; and a
plurality of quantum dots respectively disposed in at least part of
the channels.
2. The optical filter according to claim 1, wherein the ordered
porous film comprises a porous anodic aluminum oxide film or a
titanium dioxide nano-tube array film.
3. The optical filter according to claim 1, wherein the angle
between the extension direction of each of the channels and the
base substrate is ranged from 60.degree. to 90.degree..
4. The optical filter according to claim 3, wherein the angle is
ranged from 80.degree. to 90.degree..
5. The optical filter according to claim 1, wherein each of the at
least part of the channels is provided with one quantum dot or a
column of quantum dot.
6. The optical filter according to claim 1, wherein a ratio of an
average size of openings of the at least part of the channels to an
average size of the quantum dots is greater than 1 and less than
2.
7. The optical filter according to claim 1, wherein an average size
of the openings of the at least part of the channels is ranged from
2 nm to 200 nm.
8. The optical filter according to claim 7, wherein the average
size of the openings of the at least part of the channels is ranged
from 2 nm to 20 nm.
9. The optical filter according to claim 1, wherein the ordered
porous film is in direct contact with the base substrate; or the
optical filter further comprises a buffer layer disposed between
the base substrate and the ordered porous film, and the buffer
layer is in direct contact with the base substrate.
10. The optical filter according to claim 9, wherein the buffer
layer is a molybdenum metal layer and the base substrate is a glass
substrate or a quartz substrate.
11. The optical filter according to claim 1, further comprising a
black matrix disposed on a side of the ordered porous film away
from the base substrate, wherein the channels in the ordered porous
film form a plurality of optical filter regions spaced apart from
each other by the black matrix.
12. The optical filter according to claim 11, wherein the quantum
dots comprise a plurality of first quantum dots and a plurality of
second quantum dots, and the second quantum dots and the first
quantum dots are located in the different optical filter regions
and excited to emit light of different colors.
13. The optical filter according to claim 12, wherein the quantum
dots further comprise a plurality of third quantum dots, and the
third quantum dots, the first quantum dots, and the second quantum
dots are located in the different optical filter regions and
excited to emit light of different colors.
14. The optical filter according claim 1, wherein the ordered
porous film is transparent.
15. A display substrate, comprising the optical filter according to
claim 1.
16. A display device, comprising the display substrate according to
claim 15.
17. A method of manufacturing an optical filter, comprising:
forming an ordered porous film on a base substrate, wherein the
ordered porous film is formed with channels each of which having an
extension direction at least at an angle to the base substrate and
having an opening at a surface of the ordered porous film; and
immersing the ordered porous film in a solution containing quantum
dots to allow each of at least part of the channels to be filled
with at least one quantum dot.
18. The method according to claim 17, wherein a metal layer is
deposited on the base substrate; and the ordered porous film is
formed from the metal layer.
19. (canceled)
20. (canceled)
21. The method according to claim 17, wherein the channels comprise
a plurality of first channels and a plurality of second channels,
wherein after forming the ordered porous film, a first barrier
layer is formed on the ordered porous film, the first barrier layer
exposing the first channels and covering the second channels; the
ordered porous film with the first barrier layer is immersed in a
solution containing first quantum dots to allow each of at least
part of the first channels to be filled with at least one of the
first quantum dots; then a second barrier layer is formed on the
ordered porous film, the second barrier layer exposing the second
channels; and the ordered porous film with the second barrier layer
is immersed in a solution containing second quantum dots to allow
each of at least part of the second channels to be filled with at
least one of the second quantum dots, wherein the second quantum
dots and the first quantum dots are excited to emit light of
different colors.
22. (canceled)
23. (canceled)
24. The method according to claim 21, wherein the channels further
comprise a plurality of third channels, wherein after forming the
ordered porous film and before immersing the ordered porous film in
the solution containing first quantum dots, the first barrier layer
formed on the ordered porous film exposes the first channels and
covers the second channels and the third channels; after each of at
least part of the first channels is filled with at least one of the
first quantum dots, the second barrier layer formed on the ordered
porous film exposes the second channels and covers the third
channels; after each of at least part of the second channels is
filled with at least one of the second quantum dots, a third
barrier layer is formed on the ordered porous film and exposes the
third channels; and the ordered porous film with the third barrier
layer is immersed in a solution containing third quantum dots to
allow each of at least part of the third channels to be filled with
at least one of the third quantum dots, wherein the third quantum
dots, the first quantum dots and the second quantum dots are
excited to emit color of different colors.
25. (canceled)
26. (canceled)
Description
TECHNICAL FIELD
[0001] Embodiments of the present disclosure relate to an optical
filter and a method of manufacturing the same, a display substrate
and a display device.
BACKGROUND
[0002] TFT-LCD (Thin Film Transistor-Liquid Crystal Display, thin
film transistor liquid crystal display) plays an important role in
the field of display owing to its advantages such as high quality
of image display, low energy consumption, environmental
friendliness, and the like. Currently, TFT-LCD mainly comprises a
display panel and a backlight module disposed on the back side of
the display panel, wherein the display panel is formed by
assembling an array substrate and an opposing substrate, and liquid
crystal is filled in the cavity after assembling the array
substrate and the opposing substrate.
[0003] In the related art, the opposing substrate in the TFT-LCD
is, for example, a color film substrate, including an optical
filter layer which is generally distributed with color resist
patterns (sub-pixels) of red, green and blue colors, wherein the
white light emitted from the backlight module may form light of
different colors by mixing light after optical filtered by these
color resist patterns, thereby achieving color display of the
liquid crystal display.
SUMMARY
[0004] At least one embodiment of the present disclosure provides
an optical filter and a method of manufacturing the same, a display
substrate and a display device, so as to enlarge the display color
gamut of the display device.
[0005] Embodiments of the present disclosure provide an optical
filter, comprising a base substrate, an ordered porous film
disposed on the base substrate, and a plurality of quantum dots.
The ordered porous film is formed with channels each of which
having an extension direction at least at an angle to the base
substrate and having an opening at a surface of the ordered porous
film; and the plurality of quantum clots are respectively disposed
in at least part of the channels.
[0006] At least one embodiment of the present disclosure further
provides a display substrate, comprising the optical filter as
described in the above embodiments of the present disclosure.
[0007] At least one embodiment of the present disclosure further
provides a display device, comprising the display substrate as
described in the above embodiments of the present disclosure.
[0008] At least one embodiment of the present disclosure further
provides a method of manufacturing an optical filter, comprising:
forming an ordered porous film on a base substrate, wherein the
ordered porous film is formed with channels each of which having an
extension direction at least at an angle to the base substrate and
having an opening at a surface of the ordered porous film; and
immersing the ordered porous film in a solution containing quantum
dots to allow each of at least part of the channels to be filled
with at least one quantum dot.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In order to more clearly illustrate the technical solutions
of the embodiments of the present disclosure, the drawings required
to describe the embodiments or related art are briefly illustrated
below. Apparently, the drawings described below relate to only some
embodiments of the present disclosure and thus are not limitative
of the present disclosure.
[0010] FIG. 1 is a schematic view of an optical filter according to
an embodiment of the present disclosure.
[0011] FIG. 2 is a schematic view of an optical filter according to
a further embodiment of the present disclosure.
[0012] FIGS. 3A and 3B are schematic views of channels of an
ordered porous film in an optical filter according to a further
embodiment of the present disclosure.
[0013] FIGS. 4A-4F are schematic views of a method of manufacturing
an optical filter according to a further embodiment of the present
disclosure.
[0014] FIGS. 5A-5C are schematic views of a method of manufacturing
an optical filter according to a further embodiment of the present
disclosure.
[0015] FIGS. 6A-6E are schematic views of a method of manufacturing
an optical filter according to a further embodiment of the present
disclosure.
[0016] FIGS. 7A-7C are schematic views of a method of manufacturing
an optical filter according to a further embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0017] To make clearer the objects, technical solutions and
advantages of the embodiments of the present disclosure, a clear
and full description of the technical solutions of the embodiments
of the present disclosure will be made with reference to the
accompanying drawings of the embodiments of the present disclosure.
Apparently, the embodiments described are just part rather than all
of the embodiments of the present disclosure. Based on the
embodiments of the present disclosure as described, all the other
embodiments obtained by a person of ordinary skill in the art,
without any creative labor, fall within the scope of protection of
the present disclosure.
[0018] Unless otherwise defined, the technical terms or scientific
terms used in the present disclosure shall have general meanings
interpreted by a person of ordinary skill in the art to which the
present disclosure pertains. The words "first", "second" and the
like used in the present disclosure do not denote any order,
quantity or importance, but are merely used to distinguish between
different components. The words "comprise", "include" and the like
mean that the elements or objects preceding the words cover the
elements or objects listed after the words and their equivalents
thereof, without excluding other elements or objects. The words
"connected", "linked" and the like are not limited to physical or
mechanical connection, but may include electrical connection,
whether direct or indirect. The words "upper", "lower", "left",
"right" and the like are used only to represent the relative
positional relationship, and the relative positional relationship
may be changed accordingly if the absolute position of the object
described changes.
[0019] Light-emitting diode (LED) is typically used as a light
source of a backlight module, and the Full-Width Half-Maximum
(FWHM) of the light emitted by the LED is great; and the color
photoresist material in the optical filter layer itself includes
dye small molecules, and emits light of a corresponding color after
optical filtering and absorbing part of the backlight, thus
limiting the luminous efficiency of the optical filter layer.
Therefore, the color of the light formed by mixing light is impure,
resulting in a low color gamut of the image and the color
insufficiently bright and true.
[0020] Quantum dots, as a new type of semiconductor nano-material,
have many unique nano scale properties. In particular, quantum dots
have a uniform particle size, a high luminous efficiency and can
emit red light, green light or blue light with a small Full-Width
Half-Maximum (FWHM) after receiving light or being excited by
electricity, which can greatly improve the color gamut range of the
display, and thus are extensively applied in realizing wide color
gamut display.
[0021] For example, a quantum dot may be used as a backlight source
in a backlight module, which is used together with an optical
filter layer formed by using a color photoresist material in a
display panel to achieve color display and improve color gamut. In
this way, the utilization of quantum dots is low, and the
improvement in the color gamut range is limited due to the need of
the use of an optical filter layer formed by using a color
photoresist material.
[0022] At least one embodiment of the present disclosure provides
an optical filter and a method of manufacturing the same, a display
substrate and a display device, the optical filter comprising a
base substrate, an ordered porous film disposed on the base
substrate, and a plurality of quantum dots, wherein the ordered
porous film is formed with channels each of which having an
extension direction at least at an angle to the base substrate and
having an opening at a surface of the ordered porous film, and the
plurality of quantum dots are respectively disposed in at least
part of the channels.
[0023] On the one hand, the optical filter, the display substrate
having the optical filter and the display device according to the
embodiments of the present disclosure can significantly enlarge the
display color gamut of the display device; on the other hand, the
embodiments of the present disclosure can greatly improve the
utilization of quantum dots compared with the use of quantum dots
as a backlight source.
[0024] It shall be noted that the optical filter according to the
embodiments of the present disclosure can be applied to a liquid
crystal display or to any other devices requiring the use of an
optical filter.
[0025] An ordered porous film is such a film formed by using an
ordered porous material. Ordered porous materials are new
nano-structured materials that have been extensively used since the
1990s, and have the characteristics of uniform channel size,
regular channel arrangement, and continuous adjustability of the
pore size of the channel within a certain range.
Embodiment I
[0026] Embodiment I of the present disclosure provides an optical
filter 100, as illustrated in FIG. 1 and FIG. 2, comprising a base
substrate 110, an ordered porous film 120 disposed on the base
substrate 110, and a plurality of quantum dots 160. The ordered
porous film 120 is formed with channels 121 each of which having an
extension direction (i.e., a direction from one end of each of the
channels 121 adjacent to the base substrate 110 to the other end
away from the base substrate 110) at least at an angle that is not
zero to the base substrate 110 and having an opening 122 at a
surface of the ordered porous film 120, and the above plurality of
quantum dots 160 are respectively disposed in at least part of the
channels 121, i.e., some of the channels are not filled with
quantum dots.
[0027] The operational principle of the optical filter according to
the embodiment of the present disclosure is as follows: the optical
filter 100 is irradiated from the side of the base substrate 110
away from the ordered porous film 120 by, for example, excitation
light (e.g., blue light, violet light or ultraviolet light, etc.),
the excitation light being irradiated to the quantum dots 160 in
the channels 121 of the ordered porous film 120 through the base
substrate 110 so that the quantum dots 160 are excited to emit
light; the light emitted from the quantum dots 160 exits the
opening 122 of the channels 121. By enabling the quantum dots
within the channels in the same region to emit light of the same
color, the region of the optical filter can emit light of a
relatively pure color.
[0028] In order to protect the ordered porous film, especially to
make the position at which the channels of the ordered porous film
are located thin so as to ensure light transmittance at that place,
the ordered porous film is supported with a transparent base
substrate in the embodiments of the present disclosure. For
example, in the optical filter 100 according to at least one
example of the embodiment of the present disclosure, the base
substrate 110 may be a glass substrate or a quartz substrate.
Apparently, the embodiments of the present disclosure include, but
are not limited to this case.
[0029] In the embodiment of the present disclosure, the extension
direction of the channels 121 is made perpendicular to the base
substrate 110 as much as possible to facilitate irradiation of
excitation light to the quantum dots 160 in the channels 121 and to
enable the light emitted from the quantum dots 160 to exit the
opening of the channels as much as possible (that is, to avoid
irradiation to the inner walls of the channels) so as to improve
the luminous efficiency of the quantum dots and the utilization of
the light emitted.
[0030] For example, in the optical filter 100 according to at least
one example of the embodiments of the present disclosure, the angle
between the extension direction of each of the channels 121 and the
base substrate 110 may be ranged from 60.degree. to 90.degree..
[0031] Further, for example, in the optical filter 100 according to
at least one example of the embodiments of the present disclosure,
the angle between the extension direction of each of the channels
121 and the base substrate 110 may be ranged from 80.degree. to
90.degree.. For example, the angle is preferably 90.degree..
[0032] For example, in the optical filter 100 according to at least
one example of the embodiment of the present disclosure, each of at
least part of the channels 121 is provided with a column of quantum
dots 160 (the column of quantum dots are arranged substantially
along the extension direction of the channels), preferably one
quantum dot 160. This arrangement minimizes the occurrence of
agglomeration and self-quenching in the direction parallel to the
base substrate 110 between the quantum dots 160 caused by providing
each channel with rows of quantum dots, thereby increasing the
luminous efficiency of the quantum dots in each channel.
Apparently, each of at least part of the channels 121 can also be
provided with rows of quantum dots if the application requirements
are met.
[0033] For example, in the optical filter 100 according to at least
one example of the embodiment of the present disclosure, the ratio
of the average size of the opening 122 of at least part of the
channels 121 to the average size of the quantum dots 160 is greater
than 1 and less than 2. This helps to enable each of at least part
of the channels 121 to enter one quantum dot or a column of quantum
dots after immersing the porous ordered film in the solution
containing quantum dots upon making the optical filter 100, so as
to avoid low luminous efficiency of the quantum dots caused by
entry of rows of quantum dots into the same channel.
[0034] For example, in the optical filter 100 according to at least
one example of the embodiment of the present disclosure, the
opening 122 of at least part of the channels 121 may have an
average size of from 2 nm to 200 nm. This is because the average
size of quantum dots ranges from 2 nm to 200 nm. The design of the
size of the opening of the channels according to the size of the
quantum dots facilitates entry of one quantum dot or a column of
quantum dots into each channel.
[0035] For example, in the optical filter 100 according to at least
one example of the embodiment of the present disclosure, the
opening 122 of at least part of the channels 121 has an average
size of preferably from 2 nm to 20 nm. This is because the average
size of conventional quantum dots is ranged from 2 nm to 20 nm.
[0036] In summary, the size range of the above-mentioned at least
part of the channels 121 is set in accordance with the size of the
quantum dots to be provided in the at least part of the
channels.
[0037] In the embodiments of the present disclosure, the
cross-sectional shape and the opening shape of the channels 121 may
be any shapes, for example, a circle, a square, a rectangle, a
rhombus, a pentagon, a hexagon, and the like.
[0038] For example, in the optical filter 100 according to at least
one example of the embodiments of the present disclosure, the
ordered porous film 120 may include a porous anodic aluminum oxide
(AAO) film or a titanium dioxide nano-tube array film.
[0039] The porous anodic aluminum oxide (AAO) film has the
advantages of being able to form highly ordered channels, having
controllable pore size and pore spacing of channels, exhibiting
excellent thermal stability, being insulating and having a simple
preparation process. In addition, the porous anodic aluminum oxide
film is a wide band gap material having good optical properties and
high light transmission in the near ultraviolet to near infrared
band. As illustrated in FIGS. 3A and 3B, channels periodically
arranged and having a pore size of from 5 nm to 200 nm can be
prepared in the porous anodic aluminum oxide (AAO) film, where the
channels can be substantially perpendicular to the base substrate.
Therefore, by filling the channels of the porous anodic aluminum
oxide film with quantum dots as optical filters, the utilization of
the quantum dots can be greatly improved and the display color
gamut of the display device such as a liquid crystal display can be
improved as well.
[0040] The surface layer of the titanium dioxide nano-tube array
film may be formed to be similar to the morphology of the porous
anodic aluminum oxide film, and the lower layer is a nano-tube
ordered array. For example, the nano-tube may have a diameter of
from 20 nm to 100 nm.
[0041] Apparently, the embodiments of the present disclosure
include, but not limited to, porous anodic aluminum oxide films and
titanium dioxide nano-tube array films, and any porous film of
ordered channels extending in a direction substantially
perpendicular to the base substrate and having a pore size close to
the size of the quantum dots can be used in the optical filter of
the embodiments of the present disclosure. Because channels having
good uniformity and substantially perpendicular to the base
substrate are more easily formed in the porous anodic aluminum
oxide film, the porous anodic aluminum oxide film is taken as an
example in the embodiments of the present disclosure.
[0042] For example, in the optical filter 100 according to at least
one embodiment of the present disclosure, the ordered porous film
120 may be transparent, which can ensure that the position at which
the channels 121 in the ordered porous film 120 are located are
transparent, so that excitation light can be irradiated to the
quantum dots in the channels.
[0043] For example, the height of the channels 121 along the
extension direction may be equal to the thickness of the ordered
porous film 120, that is, the channels 121 may pass through the
ordered porous film 120 to ensure that the position at which the
channels 121 in the ordered porous film 120 are located are
transparent, thereby ensuring that excitation light can be
irradiated to the quantum dots in the channels. Apparently, the
height of the channels 121 along the extension direction may also
be smaller than the thickness of the ordered porous film 120 (i.e.,
the channels may be blind holes rather than through holes),
provided that the position at which the channels 121 are located
are transparent.
[0044] For example, the non-channel region of the ordered porous
film 120 may also be opaque. The degree of transparency of the
non-channel region depends upon the thickness of the ordered porous
film 120. If the ordered porous film 120 is thick, the non-channel
region may be opaque. In this case, the image displayed by the
display device using the optical filter has a purer color and a
higher color gamut; besides, if the non-channel region is opaque,
the display brightness of the display device can be improved by
providing a plurality of quantum dots (e.g., a column of quantum
dots) in each of at least part of the channels. If the ordered
porous film 120 is thin, the non-channel region may be transparent.
As such, the color gamut of the image displayed by the display
device using the optical filter is lower as compared with the case
where the non-channel region is opaque, which yet helps to improve
the display brightness.
[0045] In the optical filter 100 according to at least one example
of the embodiment of the present disclosure, as illustrated in FIG.
1, the ordered porous film 120 may be in direct contact with the
base substrate 110.
[0046] For example, as illustrated in FIG. 2, the optical filter
100 may further include a buffer layer 130 disposed between the
base substrate 110 and the ordered porous film 120, the buffer
layer 130 being in direct contact with the base substrate 110. The
adhesion between the ordered porous film 120 and the base substrate
110 can be improved by providing the buffer layer 130 between the
base substrate 110 and the ordered porous film 120.
[0047] For example, the buffer layer 130 may also be in direct
contact with the ordered porous film 120.
[0048] For example, in the optical filter 100 according to at least
one example of the embodiment of the present disclosure, the buffer
layer 130 may be a molybdenum metal layer, and the base substrate
110 may be a glass substrate or a quartz substrate. Apparently, the
embodiments of the present disclosure include, but are not limited
thereto. Any transparent film capable of improving the adhesion
between the optical filter 100 and the ordered porous film 120 may
be used as the above buffer layer.
[0049] For example, the optical filter 100 according to at least
one example of the embodiment of the present disclosure may also
include a black matrix 194 disposed on the side of the ordered
porous film 120 away from the base substrate 110, wherein the
channels 121 in the ordered porous film 120 form a plurality of
optical filter regions 150 spaced apart from each other by the
black matrix 194. The black matrix 194 serves to prevent the light
emitted from edges of different optical filter regions 150 from
being mixed. In the embodiments of the present disclosure, for
example, the channels in the ordered porous film can be highly
ordered by making the channels 121 in each optical filter region
150 substantially consistent (e.g., making the opening size, the
angle between the extension direction and the base substrate, and
the like substantially consistent). The black matrix 194 may also
be formed on the side of the base substrate 110 opposite to the
ordered porous film 120, that is, the black matrix 194 and the
ordered porous film 120 are formed on different sides of the base
substrate 110. However, the setting of the black matrix is not
limited to the above two cases in the embodiments of the present
disclosure.
[0050] For example, the optical filter 100 according to at least
one example of the embodiment of the present disclosure may also
include an encapsulation layer 140 disposed on the ordered porous
film 120 so as to protect the ordered porous film 120 and prevent
the quantum dots in the channels from falling off.
[0051] For example, the material of the encapsulation layer 140 may
be a transparent resin or the like.
[0052] For example, in the optical filter 100 according to at least
one example of the embodiment of the present disclosure, the above
quantum dots 160 may include a plurality of first quantum dots 161,
a plurality of second quantum dots 162, and a plurality of third
quantum dots 163, as illustrated in FIG. 2. The first quantum dots
161, the second quantum dots 162, and the third quantum dots 163
are located in different optical filter regions, respectively, for
example, in the first optical filter region 151, the second optical
filter region 152, and the third optical filter region 153,
respectively, and can emit light of different colors after being
excited. These optical filter regions, for example, are
corresponding to sub-pixel regions, respectively.
[0053] In the embodiments of the present disclosure, the channels
in the ordered porous film 120 may be periodically arranged, and
the channels in the same period are highly consistent. For example,
the channels in each optical filter region may form a period, or
the channels in a plurality of optical filter regions (e.g., the
first optical filter region 151, the second optical filter region
152, and the third optical filter region 153) as a whole may form a
period. Apparently the embodiments of the present disclosure
include, but are limited thereto.
[0054] For example, the plurality of first quantum dots 161, the
plurality of second quantum dots 162, and the plurality of third
quantum dots 163 can emit red light, green light, and blue light
which are symmetrical and have a narrow spectrum when excited by,
for example, blue light or violet light, so as to achieve high
color gamut color display and improve display effects.
[0055] In the embodiments of the present disclosure, the sizes of
the first, second and third quantum dots which emit light of
different colors are generally different. In this case, the average
sizes of the openings of the channels in the ordered porous film
120 may be set to be the same or may be set in accordance with the
size of the quantum dots disposed therein respectively. That is,
the opening sizes of the first channels 1211 in the first optical
filter region 151, the second channels 1212 in the second optical
filter region 152, and the third channels 1213 in the third optical
filter region 153 may be the same or different, as long as they are
greater than the average size of the quantum dots with the minimum
average size in the first, second and three quantum dots.
[0056] It should be noted that the quantum dots 160 are not limited
to three kinds, and there may also be two or more than three kinds
of quantum dots. For example, the quantum dots may include a
plurality of first quantum dots and a plurality of second quantum
dots, the second quantum dots and the first quantum dots being
located in different optical filter regions (e.g., the first
optical filter region and the second optical filter region)
respectively and can emit light of different colors after being
excited.
Embodiment II
[0057] An embodiment of the present disclosure provides a method of
manufacturing an optical filter as illustrated in FIGS. 1 and 2,
which comprises the following steps S1 and S2.
[0058] Step S1: forming an ordered porous film 120 on a base
substrate 110, wherein the ordered porous film 120 is formed with
channels 121 each of which having an extension direction at least
at an angle to the base substrate 110 and having an opening 122 at
a surface of the ordered porous film 120.
[0059] Step S2: immersing the ordered porous film 120 in a solution
containing quantum dots so that each of at least part of the
channels 121 is filled with at least one quantum dot 160.
[0060] The method of manufacturing an optical filter according to
the embodiments of the present disclosure is simple, which can
result in the production of a quantum dot optical filter with
improved color gamut by taking advantage of the narrow emission
peak of quantum dots so as to greatly enlarge the display color
gamut of the display device such as a liquid crystal display;
because the manufacturing method does not require the use of a
color photoresist material, it can improve the utilization of
quantum dots and reduce power consumption.
[0061] In order to prepare the ordered porous film onto the base
substrate while allowing the extension direction of the channels in
the ordered porous film to be perpendicular to the base substrate
as much as possible so as to enable channels as many as possible to
accommodate quantum dots, for example, in the above step S1, a
metal layer may be deposited on the base substrate, and then the
ordered porous film is formed from the metal layer.
[0062] For example, the above-mentioned metal layer may include an
aluminum metal layer. In this case, for example, a porous anodic
aluminum oxide film may be formed from the aluminum metal layer by
an anodic oxidation method. The use of the anodic oxidation method
facilitates the extension direction of the channels in the porous
anodic aluminum oxide film prepared to be perpendicular to the base
substrate as much as possible.
[0063] Apparently, the embodiments of the present disclosure
include, but are not limited to, aluminum metal layers. For
example, the above-mentioned metal layer may also include a
titanium metal layer. If a titanium metal layer is used, a titanium
dioxide nano-tube array film having an extension direction
perpendicular to the channels of the base substrate as much as
possible can be prepared by a method commonly used in the art.
[0064] For example, prior to forming an ordered porous film from
the above metal layer, the method according to at least one example
of the embodiment of the present disclosure may further comprise:
forming a protective layer film on the metal layer, and then
patterning the protective layer film to form a protective layer
having a plurality of hollow portions arranged in a matrix, each of
the hollow portions being corresponding to a partial area of the
metal layer. On the one hand, the protective layer facilitates a
high consistency of the channels formed by the ordered porous film
in the area corresponding to the same hollow portion so as to
ensure the periodicity of the channels in the ordered porous film;
on the other hand, the protective layer can protect the position of
the black matrix to be formed by the ordered porous film so as to
ensure the consistency of the black matrix pattern.
[0065] For example, the material of the protective layer film may
be a photoresist. As such, it is only necessary to expose and
develop the protective layer film upon patterning the same, and the
steps such as etching and the like are not required, i.e., the
production process is quite simple.
[0066] For example, the material of the protective layer film may
be a black photoresist. In this way, after forming the ordered
porous film, the black photoresist material may be applied directly
to the protective layer formed so as to form a black matrix without
additionally adding the step of etching the protective layer,
thereby simplifying the process.
[0067] For example, prior to forming the above metal layer on the
base substrate, the manufacturing method according to at least one
example of the embodiment of the present disclosure may further
include: forming a buffer layer on the base substrate, the buffer
layer being in direct contact with the base substrate. As such, the
adhesion between the base substrate and the above metal layer
subsequently formed on the buffer layer can be improved.
[0068] For example, as illustrated in FIGS. 4A to 4F, the method of
manufacturing the optical filter 100 according to an embodiment of
the present disclosure may include the following steps S01 to
S07.
[0069] Step S01: as illustrated in FIG. 4A, a buffer layer 130 is
formed on the base substrate 110, the buffer layer 130 being in
direct contact with the base substrate 110 so as to improve the
adhesion between the base substrate 110 and the metal layer (not
shown in FIG. 4A) to be formed on the buffer layer 130.
[0070] In this step, for example, the buffer layer 130 may be a
molybdenum metal layer given that the base substrate is a glass
substrate or a quartz substrate. For example, the molybdenum metal
layer may be formed by a conventional means in the art such as
magnetron sputtering.
[0071] Step S02: as illustrated in FIG. 4B, a metal layer 170 is
deposited on the buffer layer 130.
[0072] In this step, for example, the metal layer 170 may be an
aluminum metal layer. For example, the metal layer 170 may be
deposited on the buffer layer 130 by a conventional means in the
art such as magnetron sputtering.
[0073] Step S03: as illustrated in FIG. 4C, a protective layer film
180 is formed on the metal layer 170.
[0074] In this step, for example, the protective layer film 180 may
be formed by coating the metal layer 170 with a black photoresist.
For example, the protective layer film may have a film thickness of
from 1 .mu.m to 2 .mu.m and an optical density (OD) of greater than
or equal to 4.0.
[0075] Step S04: as illustrated in FIG. 4D, the protective layer
film 180 is exposed by a mask plate 200; as illustrated in FIG. 4E,
a protective layer 181 having a plurality of hollow portions 182 is
formed after development, the plurality of hollow portions 182
being arranged in a matrix and each of the hollow portions 182
being corresponding to a partial area of the metal layer 170.
[0076] For example, the plurality of hollow portions 182 may
correspond to a plurality of optical filter regions 150 in
Embodiment I, respectively.
[0077] Step S05: as illustrated in FIG. 4F, an ordered porous film
120 is formed from the metal layer 170, wherein the ordered porous
film 120 is formed with channels 121.
[0078] For example, the channels 121 may have the same opening
size; alternatively, the channels 121 may include a plurality of
first channels 1211, second channels 1212 and third channels 1213
which are periodically arranged, and the three types of channels
may have different opening sizes.
[0079] For example, in this step, an ordered porous film 120 may be
formed from the metal layer 170 by an anodic oxidation method. For
example, the preparation of an ordered porous film 120 from the
aluminum metal layer by an anodic oxidation method may include the
following steps S051 to S053.
[0080] Step S051: primary oxidation is performed.
[0081] For example, in a 0.25.about.0.4 mol/L oxalic acid solution,
a DC voltage of 35.about.45V is maintained, and ice water bath is
used to maintain a constant temperature about 10.degree. C. lower
than room temperature. The aluminum metal layer on the base
substrate is subjected to primary oxidation, for example, for 3 to
5 hours (the specific time may be adjusted according to the desired
structure).
[0082] Step S052: after primary oxidation, the base substrate
subjected to the above step S051 is rinsed and dried.
[0083] For example, the base substrate subjected to the above step
S051 may be rinsed by means of a sprinkler using distilled
water.
[0084] Step S053: secondary oxidation is performed.
[0085] The base substrate subjected to step S052 is placed in a
mixed solution of phosphoric acid (5 to 8% by weight) and chromic
acid (1 to 2% by weight) at 80.degree. C., the Al.sub.2O.sub.3 film
formed on the surface of the aluminum metal layer by primary
oxidation is corroded, and secondary oxidation is then performed on
the surface of a hexagonal pit array structure formed after primary
oxidation, where the other conditions of the secondary oxidation
are the same as that of the primary oxidation and the secondary
oxidation lasts about eight to 11 hours.
[0086] The above process of making the porous anodic aluminum oxide
film by the anodic oxidation method is only for illustrative
purposes. The embodiments of the present disclosure include, but
are not limited thereto. In addition, a person skilled in the art
can adjust the diameter, shape, periodicity and the like of the
channels formed on the surface of the base substrate by adjusting
the production process of the porous anodic aluminum oxide film
(for example, by adjusting the type of the acid solution, the
conditions for oxidation, etc.). No further detail will be provided
herein.
[0087] Step S06: the ordered porous film 120 is immersed in a
solution containing quantum dots so that each of at least part of
the channels 121 is filled with at least one quantum dot 160, as
illustrated in FIGS. 1 and 2.
[0088] In this step, the solution containing quantum dots may be
formed by dispersing the material of quantum dots into a solvent
commonly used in the art such as water, ethanol or acetone.
[0089] Step S07: a black matrix layer 194 and an encapsulation
layer 140 are formed on the ordered porous film 120, as illustrated
in FIGS. 1 and 2.
[0090] In this step, the solvent in the solution containing quantum
dots in the channels 121 is removed before the encapsulation layer
140 is formed so that only corresponding quantum dots are retained
in the channels. For example, a volatile solvent may be used in the
preparation of the solution containing quantum dots so as to
facilitate removal of the solvent in the channels.
[0091] In the method of manufacturing an optical filter according
to the embodiments of the present disclosure, a porous anodic
aluminum oxide film having good periodicity and extending in a
direction substantially perpendicular to the channels of the base
substrate can be prepared by forming an aluminum metal layer on the
base substrate and then using anodic oxidation techniques; the
channels of corresponding optical filter regions can be filled with
quantum dots by using a black photoresist and the processes of
exposure and development. The process according to the embodiments
of the present disclosure is simple, and the quantum dots of the
optical filter prepared have high utilization efficiency and
luminous efficiency, and can greatly improve the color gamut of the
display device.
Embodiment III
[0092] The present embodiment differs from Embodiment II mainly in
that: the above plurality of quantum dots include a plurality of
first quantum dots and a plurality of second quantum dots, the
second quantum dots and the first quantum dots being excited to
emit light of different colors. Accordingly, the above channels in
the ordered porous film 120 may include a plurality of first
channels and a plurality of second channels. In this case, the step
S2 described above may include, for example, the following steps
S21 to S24.
[0093] Step S21: as illustrated in FIG. 5A, after forming the
ordered porous film 120, a first barrier layer 191 is formed on the
ordered porous film 120, wherein the first barrier layer 191
exposes the first channels 1211 and covers the second channels
1212.
[0094] For example, the material of the first barrier layer may be
a black photoresist. As such, the first barrier layer can be formed
by exposure and development without any etching step, thereby
simplifying the process.
[0095] Step S22: as illustrated in FIG. 5B, the ordered porous film
120 on which the first barrier layer 191 is formed is immersed in a
solution containing first quantum dots so that each of at least
part of the first channels 1211 is filled with at least one of the
first quantum dots 161.
[0096] In this step, the first barrier layer 191 can prevent the
first quantum dots 161 from entering the second channels 1212.
[0097] For example, the solution containing first quantum dots may
be formed by dispersing the material of quantum dots that emits a
first color light (e.g., red light) into a solvent commonly used in
the art such as water, ethanol or acetone.
[0098] Step S23: as illustrated in FIG. 5C, a second barrier layer
192 is formed on the ordered porous film 120, wherein the second
barrier layer 192 exposes the second channels 1212.
[0099] For example, the material of the second barrier layer may be
a black photoresist. As such, the process for making the second
barrier layer is simplified.
[0100] Step S24: as illustrated in FIG. 5C, the ordered porous film
120 on which the second barrier layer 192 is formed is immersed in
a solution containing second quantum dots 162 so that each of at
least part of the second channels 1212 is filled with at least one
of the second quantum dots 162.
[0101] For example, the solution containing second quantum dots may
be formed by dispersing the material of quantum dots that emits a
second color light (e.g., green light) into a solvent commonly used
in the art such as water, ethanol or acetone.
[0102] For example, in the above step S23, the second barrier layer
192 may cover the first channels 1211, for example, a new second
barrier layer 192 is formed after removing the second barrier layer
192 that has been used before. Thus, in a subsequent step S24, the
second barrier layer 192 may prevent the second quantum dots 162
from entering the first channels 1211 and prevent the second
quantum dots 162 from affecting the quantum dots in the first
channels 1211.
[0103] As for the production and setting of other components in the
optical filter, reference can be made to the relevant description
in Embodiments I and II. Thus, no further detail will be provided
herein.
Embodiment IV
[0104] The present embodiment differs from Embodiment III mainly in
that: the above plurality of quantum dots further comprise a
plurality of third quantum dots, the third quantum dots, the second
quantum dots and the first quantum dots being excited to emit light
of different colors. Accordingly, the above channels in the ordered
porous film may further include a plurality of third channels. In
this case, the difference between step S2 in the present embodiment
and step S2 in Embodiment III is as follows.
[0105] In step S21, i.e., after forming the ordered porous film 120
and immersing the ordered porous film 120 in a solution containing
first quantum dots, as illustrated in FIG. 6A, the first barrier
layer 191 formed on the ordered porous film 120 exposes the first
channels 1211 and covers the second channels 1212 and the third
channels 1213 so that the first barrier layer 191 can prevent the
first quantum dots 161 from entering the second channels 1212 and
the third channels 1213 in step S22.
[0106] In step S23, i.e., after filling each of at least part of
the first channels 1211 with at least one of the first quantum dots
161 as illustrated in FIG. 6B, the second barrier layer 192 formed
on the ordered porous film 120 exposes the second channels 1212 and
covers the third channels 1213 so that the second barrier layer 192
can prevent the second quantum dots 162 from entering the third
channels 1213 in step S24.
[0107] In addition, as compared with step S2 in Embodiment III,
step S2 in the manufacturing method according to the present
embodiment further comprises the following steps S25 and S26:
[0108] Step S25: as illustrated in FIG. 6D, a third barrier layer
193 is formed on the ordered porous film 120, wherein the third
barrier layer 193 exposes the third channels 1213.
[0109] For example, the material of the third barrier layer may be
a black photoresist. As such, the third barrier layer can be formed
by exposure and development without any etching step, thereby
simplifying the process.
[0110] Step S26: as illustrated in FIG. 6D, the ordered porous film
120 on which the third barrier layer 193 is formed is immersed in a
solution containing third quantum dots 163 so that each of at least
part of the third channels 1213 is filled with at least one of the
third quantum dots 163.
[0111] In this step, the third barrier layer 193 may be used
directly as a black matrix 194 so as to simplify the process.
[0112] For example, the solution containing third quantum dots may
be formed by dispersing the material of quantum dos that emits a
third color light (e.g., blue light) into a solvent commonly used
in the art such as water, ethanol or acetone.
[0113] Apparently, the manufacturing method according to the
present embodiment may also comprise the step of applying an
encapsulation layer 140 on the ordered porous film 120 and the
black matrix 194, as illustrated in FIG. 6E.
[0114] As for the production and setting of other components in the
optical filter, reference can be made to the relevant description
in Embodiments I and II. Thus, no further detail will be provided
herein.
Embodiment V
[0115] The present embodiment differs from Embodiment IV mainly in
that: the second barrier layer further covers the first channels,
and/or the third barrier layer covers the first channels and the
second channels.
[0116] For example, if the second barrier layer further covers the
first channels and the third barrier layer covers the first
channels and the second channels, the difference between step S2 in
the present embodiment and step S2 in Embodiment IV is as
follows.
[0117] In step S23, as illustrated in FIG. 7A, the second barrier
layer 192 formed on the ordered porous film 120 exposes the second
channels 1212 and covers the first channels 1211 and the third
channels 1213 so that the second barrier layer 192 can prevent the
second quantum dots 162 from entering the first channels 1211 and
the third channels 1213 in step S24.
[0118] In step S25, as illustrated in FIG. 7B, the third barrier
layer 193 formed on the ordered porous film 120 exposes the third
channels 1213 and covers the first channels 1211 and the second
channels 1212 so that the third barrier layer 193 can prevent the
third quantum dots 163 from entering the first channels 1211 and
the second channels 1212 in step S26.
[0119] In addition, as compared with step S2 in Embodiment IV, step
S2 in the manufacturing method according to the present embodiment
may further include step S27, that is, the third barrier layer 193
is patterned (for example, the third barrier layer is exposed and
developed) to form a black matrix 194, as illustrated in FIG.
7C.
[0120] As for the production and setting of other components in the
optical filter, reference can be made to the relevant description
in Embodiments I and II. Thus, no further detail will be provided
herein.
[0121] In the method of manufacturing an optical filter according
to the above embodiments of the present disclosure, the quantum
dots are not limited to two or three kinds, and there may be more
than three kinds of quantum dots. If there are more than three
kinds of quantum dots, the manner in which these quantum dots are
filled in the corresponding channels is similar to the manner in
which each kind of quantum dots in the above embodiments are filled
in the corresponding channels, and thus no further detail will be
provided herein. For example, if the excitation light used is blue
light, two regions (sub-pixels) including quantum dots emitting red
light and green light respectively can be formed, and the third
region is filled with no quantum dots to make it transmissible to
blue light, thereby achieving three primary colors.
[0122] At least one embodiment of the present disclosure further
provides a display substrate, comprising the optical filter as
described in any one of the embodiments of the present
disclosure.
[0123] For example, the display substrate may be a color film
substrate or an array substrate.
[0124] At least one embodiment of the present disclosure further
provides a display device, comprising the display substrate as
described in any one of the embodiments of the present
disclosure.
[0125] For example, the display device may be any product or
component having a display function such as a liquid crystal panel,
a mobile phone, a tablet, a TV set, a display, a laptop, a digital
photo frame, a navigator, or the like.
[0126] The optical filter, the display substrate having the optical
filter and the display device according to the embodiments of the
present disclosure can greatly enlarge the display color gamut of a
display device such as a liquid crystal display, and improve photon
efficiency and reduce power consumption as well.
[0127] It shall be noted that:
[0128] (1) the drawings of the embodiments of the present
disclosure only relate to the structures involved in the
embodiments of the present disclosure, and reference may be made to
conventional designs for other structures;
[0129] (2) the film thickness and shape of each layer in the
drawings do not reflect the true scales, but merely aim to
illustrate the contents of the embodiments of the present
disclosure; and
[0130] (3) the embodiments of the present disclosure and the
features in the embodiments may be combined with each other if they
are not contradictory.
[0131] The above are merely exemplary embodiments of the present
disclosure, and are not intended to limit the scope of protection
of the present disclosure, which is yet determined by the appended
claims.
[0132] The present application claims the priority of the Chinese
patent application No. 201510728954.9 submitted on Oct. 30, 2015,
and the content disclosed in the above Chinese patent application
is incorporated herein by reference as part of the present
application.
* * * * *