U.S. patent application number 13/942464 was filed with the patent office on 2013-11-14 for substrate for an organic electronic element and a production method therefor.
The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Seong Su JANG, Min Soo Kang, Yeon Keun Lee, Kyoung Sik Moon.
Application Number | 20130302565 13/942464 |
Document ID | / |
Family ID | 45840365 |
Filed Date | 2013-11-14 |
United States Patent
Application |
20130302565 |
Kind Code |
A1 |
JANG; Seong Su ; et
al. |
November 14, 2013 |
SUBSTRATE FOR AN ORGANIC ELECTRONIC ELEMENT AND A PRODUCTION METHOD
THEREFOR
Abstract
The present invention relates to a substrate for an organic
electronic element that enables surface resistance to be reduced
and light-extraction efficiency improved, the substrate including:
a base substrate; a scattering layer which is formed on the base
substrate and includes an conductive pattern for reducing the
surface resistance of an electrode, scattering particles for
scattering light and a binder, and which forms an uneven structure
in the surface opposite the base substrate; and a planarizing layer
which is formed on the scattering layer and flattens the surface
undulations caused by the uneven structure of the scattering layer,
wherein the refractive index (Na) of the scattering particles and
the refractive index (Nb) of the planarizing layer satisfy the
relationship in formula 1 below. [Formula 1] |Na-Nb|.gtoreq.0.3. In
the formula as used herein, Na signifies the refractive index of
the scattering particles and Nb signifies the refractive index of
the planarizing layer.
Inventors: |
JANG; Seong Su; (Daejeon,
KR) ; Lee; Yeon Keun; (Daejeon, KR) ; Moon;
Kyoung Sik; (Daejeon, KR) ; Kang; Min Soo;
(Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Family ID: |
45840365 |
Appl. No.: |
13/942464 |
Filed: |
July 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13878151 |
Jun 20, 2013 |
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PCT/KR2011/007432 |
Oct 7, 2011 |
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13942464 |
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Current U.S.
Class: |
428/148 ; 427/58;
428/143; 428/149 |
Current CPC
Class: |
C23C 30/00 20130101;
Y10T 428/24372 20150115; H01L 51/5275 20130101; H01L 2251/5369
20130101; H01L 51/5212 20130101; Y10T 428/24413 20150115; Y10T
428/24421 20150115; G02B 5/0221 20130101; H01L 51/5268 20130101;
Y10T 428/24364 20150115 |
Class at
Publication: |
428/148 ;
428/143; 428/149; 427/58 |
International
Class: |
H01L 51/52 20060101
H01L051/52 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2010 |
KR |
10-2010-0097979 |
May 18, 2011 |
KR |
10-2011-0046909 |
Claims
1. A substrate for an organic electronic element comprising: a base
substrate; a scattering layer comprising a conductive pattern
configured to lower a sheet resistance of an electrode, scattering
particles scattering light and a binder; forming an uneven
structure on the surface opposite to the base substrate, and formed
on the base substrate; and a planarizing layer formed on the
scattering layer and planarizing the surface undulations caused by
the uneven structure of the scattering layer, wherein the
refractive index (Na) of the scattering particles and the
refractive index (Nb) of the planarizing layer satisfy the
relationship in formula 1 below: |Na-Nb|.gtoreq.0.3 (1) wherein the
"Na" represents the refractive index of the scattering particles
and the "Nb" represents the refractive index of the planarizing
layer.
2. The substrate of claim 1, wherein one surface of the conductive
pattern is exposed on the planarized surface formed by the
planarizing layer, and a ratio of the area of the exposed
conductive pattern on the surface of the planarizing layer with
respect to the area of the entire surface of the planarizing
surface is from 0.001% to 50%.
3. The substrate of claim 1, wherein a height of the conductive
pattern is from 0.01 .mu.m to 50 .mu.m, and a width of the
conductive pattern is from 0.1 .mu.m to 500 .mu.m.
4. The substrate of claim 1, wherein the conductive pattern
comprises at least one selected from the group consisting of Ag,
Au, Al, Cu, Cr, and Mo/Al/Mo.
5. The substrate of claim 1, wherein the conductive pattern is in a
network structure of conductive material comprising carbon, a metal
paste comprising silver or a silver (Ag) paste.
6. The substrate of claim 1, wherein the refractive index of the
scattering particles (Na) is from 1.0 to 2.0, and the refractive
index of the planarizing layer (Nb) is from 1.7 to 2.5.
7. The substrate of claim 1, wherein the refractive index (Na) of
the scattering particles is from 2.0 to 3.5, and the refractive
index (Nb) of the planarizing layer is from 1.7 to 2.5.
8. The substrate of claim 1, wherein the scattering particle is at
least one selected from the group consisting of silicon, silica,
glass, titanium oxide, magnesium fluoride, zirconium oxide,
alumina, cerium oxide, hafnium oxide, niobium pentoxide, tantalum
pentoxide, indium oxide, tin oxide, indium tin oxide, zinc oxide,
zinc sulfide, calcium carbonate, barium sulfate, silicon nitride,
and aluminum nitride.
9. The substrate of claim 1, wherein an average diameter of the
scattering particles is from 0.01 .mu.m to 20 .mu.m.
10. The substrate of claim 1, wherein the binder in the scattering
layer is an inorganic or organic-inorganic composite binder.
11. The substrate of claim 10, wherein the binder in the scattering
layer is at least one selected from the group consisting of silicon
oxide; silicon nitride; silicon oxynitride; alumina; and an
inorganic or organic-inorganic composite based on a siloxane
bond.
12. The substrate of claim 1, wherein the planarizing layer
comprises an inorganic binder or organic-inorganic composite
binder.
13. The substrate of claim 12, wherein the planarizing layer
comprises at least one selected from the group consisting of
silicon oxide; silicon nitride; silicon oxynitride; alumina; and an
inorganic or organic-inorganic composite based on a siloxane
bond.
14. The substrate of claim 12, wherein the planarizing layer
further comprises a high refractive filler.
15. The substrate of claim 14, wherein the high refractive filler
is at least one selected from the group consisting of alumina,
aluminum nitride, zirconium oxide, titanium oxide, cerium oxide,
hafnium oxide, niobium pentoxide, tantalum pentoxide, indium oxide,
tin oxide, indium tin oxide, zinc oxide, silicon, zinc sulfide,
calcium carbonate, barium sulfate and silicon nitride.
16. A method for preparing a substrate for an organic electronic
element comprising forming a conductive pattern on a base
substrate; forming a scattering layer by filling a coating solution
comprising a binder and scattering particles on a base substrate,
on which the conductive patterns are formed; and forming a
planarizing layer on the formed scattering layer.
17. The method of claim 16, wherein the forming of the scattering
layer is conducted by CVD, PVD or sol-gel coating.
18. The method of claim 16, further comprising polishing an upper
surface of the formed planarizing layer after the forming of the
planarizing layer.
19. An organic electronic device comprising the substrate of claim
1 and an organic electronic element formed on the substrate.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to a substrate for an organic
electronic element having a novel structure, a method for preparing
the substrate, and an organic electronic device including the
substrate.
[0003] 2. Discussion of Related Art
[0004] An organic electronic device denotes a device capable of
inducing a current of charge between electrodes and organic
materials using holes and/or electrons. The organic electronic
device may be, in accordance with its working mechanism, an
electronic device in which excitons formed in an organic layer by
photons introduced from outside light source to the device are
separated into electrons and holes, and the separated electrons and
holes are transported to different electrodes, thereby forming a
current generator; or an electronic device in which holes and/or
electrons are introduced into an organic material by applying a
voltage or a current to at least two electrodes, and the device
functions by the introduced electrons and holes. Types of organic
electronic devices include an organic light emitting diode (OLED),
an organic solar cell, an organic photo-conductor (OPC) drum and an
organic transistor.
[0005] An organic light emitting diode denotes a self-emissive type
device which uses an electroluminescence phenomenon of emitting
light when a current is applied to a luminescent organic compound.
The organic light emitting diode is garnering attention as an
advanced material in various industries, such as displays and
lighting, as it has advantages of superior thermal stability and
low driving voltage.
SUMMARY OF THE INVENTION
[0006] The purpose of the present invention is to provide a
substrate for an organic electronic element having a novel
structure, a method for preparing the substrate, and the organic
electronic device including the substrate.
[0007] One aspect of the present invention provides a substrate for
an organic electronic element including a base substrate; a
scattering layer which is formed on the base substrate and includes
an conductive pattern for reducing surface resistance of an
electrode, scattering particles for scattering light and a binder,
and which has an uneven structure formed in a surface opposite to
the base substrate; and a planarizing layer which is formed on the
scattering layer and flattens surface undulations caused by the
uneven structure of the scattering layer, wherein the refractive
index (Na) of the scattering particles and the refractive index
(Nb) of the planarizing layer satisfy the relationship in formula 1
below:
|Na-Nb|.gtoreq.0.3 (1)
[0008] wherein Na stands for the refractive index of the scattering
particles and Nb stands for the refractive index of the planarizing
layer.
[0009] Another aspect of the present invention provides a method
for preparing the substrate, and an organic electronic device
including the substrate.
EFFECT
[0010] The substrate for an organic electronic element according to
the present invention can improve light extraction efficiency
without a decrease of device performance, and enables uniform
application of voltage over the entire device. Also, the present
invention has an advantage that the preparation method is
simple.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a schematic diagram showing a method for
preparing the substrate for an organic electronic element according
to an embodiment of the present invention.
[0012] FIG. 2 illustrates a schematic diagram showing a cross
section of the substrate for an organic electronic element
according to an embodiment of the present invention.
[0013] FIG. 3 illustrates a schematic diagram showing a cross
section of the organic electronic device according to an embodiment
of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0014] One exemplary substrate for an organic electronic element
according to the present invention includes a base substrate; a
scattering layer which is formed on the base substrate and includes
an conductive pattern for reducing surface resistance of an
electrode, scattering particles for scattering light and a binder,
and which has an uneven structure formed in a surface opposite to
the base substrate; and a planarizing layer which is formed on the
scattering layer and flattens surface undulations caused by the
uneven structure of the scattering layer, wherein the refractive
index (Na) of the scattering particles and the refractive index
(Nb) of the planarizing layer satisfy the relationship in formula 1
below:
|Na-Nb|.gtoreq.0.3 (1)
[0015] wherein Na stands for the refractive index of the scattering
particles and Nb stands for the refractive index of the planarizing
layer.
[0016] In the present invention, the electronically conductive
pattern is formed in the scattering layer, and thus surface
resistance of the device may be moderately or slowly increased.
Indium tin oxide (ITO) is generally used as a first electrode
stacked on a substrate. However, an ITO electrode generates surface
resistance of about 10 .OMEGA./cm.sup.2. The surface resistance
increases as an area of the device increases, and the increased
surface resistance deteriorates a uniformity of a light-emitting
surface and makes difficult to increase an area of the device. The
substrate for an organic electronic element according to the
present invention forms an electronically conductive pattern in a
scattering layer, and thus the surface resistance of the first
electrode may be decreased, thereby increasing the uniformity of
emission.
[0017] In one exemplary embodiment of the present invention, a
surface of the conductive pattern may be exposed to a flattened
surface formed by the planarizing layer. The electronically
conductive pattern exposed to the flattened surface formed by the
planarizing layer may be electronically connected with an electrode
layer to be formed afterwards. In another exemplary embodiment of
the present invention, an area ratio of the conductive pattern
exposed to the flattened surface may be from 0.001% to 50%,
particularly from 0.01% to 30%, more particularly 10% to 20%,
relative to a total area of the flattened surface.
[0018] In a further exemplary embodiment of the present invention,
a height of the conductive pattern may be from 0.01 .mu.m to 50
.mu.m, particularly from 0.1 .mu.m to 10 .mu.m, and a width of the
conductive pattern may be from 0.1 .mu.m to 500 .mu.m, particularly
from 1 .mu.m to 100 .mu.m.
[0019] In addition, the conductive pattern may be any kind of
material as long as the material has electrical conductivity, and
may be made of at least one selected from the group consisting of
Ag, Au, Al, Cu, Cr, and Mo/Al/Mo. More particularly, the conductive
pattern may be a network structure of a silver (Ag) paste, a metal
paste including silver or a conductive material including carbon. A
form of the metallic conductive pattern is not particularly
limited, and may be, for example, a form in which plural metallic
conductive lines are in parallel, a diagonal form, a mesh form, a
honeycomb form or an amorphous form.
[0020] In an organic electronic element, for instance, in an
organic light emitting diode, a total reflection occurs in the
interfaces of each layer constituting the element. In particular, a
first total reflection of the light generated from the organic
layer occurs in the interface between a transparent electrode of
which a refractive index is at least 1.8 and a glass substrate of
which a refractive index is at least 1.5. Also, a second total
reflection of the light passing through the glass substrate occurs
in the interface between the glass substrate of which a refractive
index is 1.8 and air of which a refractive index is 1.0. Due to the
total reflections inside the device, the emission efficiency may be
deteriorated and the brightness may be decreased.
[0021] In the present invention, the scattering particles which
scatter light are located between the formed conductive patterns,
which may lead to an increase in the inner light extraction
efficiency. In particular, a scattering effect over the light
directed from the planarizing layer to the scattering layer may be
increased by making a large difference in the refractive indexes of
the scattering particles and the planarizing layer, thereby
minimizing the loss of reflection inside the device. According to a
specific exemplary embodiment of the present invention, the
refractive index of the scattering particles (Na) may be from 1.0
to 2.0, and the refractive index of the planarizing layer (Nb) may
be from 1.7 to 2.5, more particularly, the refractive index of the
scattering particles (Na) may be from 1.2 to 1.8, and the
refractive index of the planarizing layer (Nb) may be from 1.8 to
2.0. According to a different specific exemplary embodiment of the
present invention, the refractive index of the scattering particles
(Na) may be from 2.0 to 3.5, and the refractive index of the
planarizing layer (Nb) may be from 1.7 to 2.5, more particularly,
the refractive index of the scattering particles (Na) may be from
2.2 to 3.0, and the refractive index of the planarizing layer (Nb)
may be from 1.8 to 2.0.
[0022] In the present invention, the term "refractive index"
denotes a refractive index measured for a light having a wavelength
of from 400 nm to 450 nm under vacuum conditions.
[0023] The base substrate as used herein is not particularly
limited, and may be a transparent base substrate, such as
translucent plastic substrate or a glass substrate.
[0024] The scattering particles as used herein are not particularly
limited as long as they can scatter light using the difference of
refractive index with the planarizing layer, and may be at least
one selected from the group consisting of silicon, silica, glass,
titanium oxide, magnesium fluoride, zirconium oxide, alumina,
cerium oxide, hafnium oxide, niobium pentoxide, tantalum pentoxide,
indium oxide, tin oxide, indium tin oxide, zinc oxide, zinc
sulfide, calcium carbonate, barium sulfate, silicon nitride, and
aluminum nitride.
[0025] The scattering particles as used herein may be formed on the
base substrate by the connection with the binder, and may be a
single layer or multiple layers, or may form an uneven stacked
structure. Preferably, the scattering particles as used herein may
be in a structure of a single layer formed on the base substrate.
When the scattering particles as used herein are formed as a single
layer, light may be uniformly distributed, which enables uniform
emission throughout an entire light-emitting surface. The
scattering particles as used herein may be a sphere, an ellipsoid
or an amorphous form, preferably a sphere or an ellipsoid form. An
average diameter of the scattering particles may be from 0.01 .mu.m
to 20 .mu.m, preferably from 0.1 .mu.m to 5 .mu.m.
[0026] The binder in the scattering layer as used herein is not
particularly limited, and may be an organic and inorganic or
organic-inorganic composite binder. According to a specific
exemplary embodiment of the present invention, the binder may be an
inorganic or organic-inorganic composite binder. The inorganic or
organic-inorganic composite binder has superior thermal stability
and chemical resistance compared with an organic binder and as such
is advantageous in terms of device performance, especially
lifespan. Also, the deterioration which may occur during the
process of manufacturing a device, such as a high temperature
process at equal to or more than 150.degree. C., a photo process
and an etching process, does not occur, and as such, it is
advantageous for the production of various devices. Preferably, the
binder as used herein may be at least one selected from the group
consisting of silicon oxide, silicon nitride, silicon oxynitride,
alumina, and an inorganic or organic-inorganic composite of which
basis is siloxane bond. For instance, the inorganic binder based on
a [Si--O] bond formed by polycondensation of siloxane, or the
organic-inorganic composite in which alkyl groups are not
completely removed in the siloxane bonds may be used.
[0027] The planarizing layer as used herein may include an
inorganic binder or organic-inorganic composite binder. For
instance, the planarizing layer may include at least one selected
from the group consisting of silicon nitride, silicon oxynitride,
alumina, and an inorganic or organic-inorganic composite based on a
siloxane bond (Si--O).
[0028] The planarizing layer as used herein may further include a
highly refractive filler. The highly refractive filler as used
herein is intended to reduce the difference of refractive indexes
of the planarizing layer and the organic device. The highly
refractive filler as used herein is not particularly limited as
long as it can increase the refractive index by being dispersed in
the planarizing layer, and may be at least one selected from the
group consisting of alumina, aluminum nitride, zirconium oxide,
titanium oxide, cerium oxide, hafnium oxide, niobium pentoxide,
tantalum pentoxide, indium oxide, tin oxide, indium tin oxide, zinc
oxide, silicon, zinc sulfide, calcium carbonate, barium sulfate and
silicon nitride. For instance, the highly refractive filler as used
herein may be titanium dioxide.
[0029] A thickness of the planarizing layer as used herein may be
appropriately controlled depending on the device characteristics.
In order to increase the light extraction efficiency, the average
thickness of the planarizing layer may be 0.5 times or at least 2
times an average diameter of the scattering particles, and for
instance, may be in the range from 0.5 times to 10 times, or 1 time
to 5 times.
[0030] FIG. 1 illustrates a schematic diagram of stacked structure
of the substrate for an organic electronic element according to an
example of the present invention. Referring to FIG. 1, a scattering
layer 20 including scattering particles 40 and an conductive
pattern 30 is formed on a base substrate 10, and an uneven
structure is formed in the opposite surface to the base substrate
10 in the substrate for an organic electronic element according to
the present invention. The planarizing layer 21 is formed on the
uneven structure of the scattering layer. The organic electronic
element or so on may be further stacked on the planarizing layer
21.
[0031] The present invention also provides a method for preparing
the substrate for an organic electronic element.
[0032] In an exemplary embodiment of the present invention, the
method for preparing a substrate for an organic electronic element
may include:
[0033] forming an conductive pattern on a base substrate;
[0034] forming a scattering layer on the base substrate on which
the conductive pattern is formed by filling a coating solution
including a binder and scattering particles; and
[0035] forming a planarizing layer on the formed scattering
layer.
[0036] The forming of the conductive pattern on the base substrate
may be performed, for example, using a roller printing method on a
sacrificial substrate. The material and shape of the conductive
pattern are the same as explained above.
[0037] The forming of the scattering layer as used herein may be
conducted by chemical vapor deposition (CVD), physical vapor
deposition (PVD) or sol-gel coating. For example, the forming of
the scattering layer may include applying a coating solution
including an inorganic or organic-inorganic composite binder and
scattering particles on a base substrate; and forming a matrix by
polycondensation of the binder contained in the coating solution.
The uneven structure may be formed by the scattering particles
during the process of polycondensation of the binder contained in
the coating solution.
[0038] In addition, the forming of the planarizing layer as used
herein may be conducted by chemical vapor deposition (CVD),
physical vapor deposition (PVD) or sol-gel coating. For example,
the forming of the planarizing layer as used herein may include
applying a coating solution including an inorganic binder and a
highly refractive filler on the scattering layer; and forming a
matrix by polycondensation of the binder contained in the coating
solution.
[0039] In a further exemplary embodiment of the present invention,
the method may further include polishing an upper surface of the
formed planarizing layer after the forming of the planarizing
layer. Through the polishing process, the upper surface of
planarizing layer may be formed more uniformly. Also, an electrical
connection between the conductive pattern to be exposed to the
upper surface of the planarizing layer and a first electrode to be
stacked afterwards may be facilitated. Types of the process of
polishing an upper surface of the planarizing layer are not
particularly limited, and it may be performed, for instance, by a
chemical mechanical polishing (CMP) process.
[0040] FIG. 2 illustrates a schematic diagram showing a process of
manufacturing the organic electronic device according to an example
of the present invention. First, an conductive pattern 30 is formed
on a glass substrate 10 in operation (A). The conductive pattern 30
may be formed by a roll printing method. A scattering layer may be
formed by applying a coating solution in which scattering particles
are dispersed in an inorganic or organic-inorganic composite binder
on the base substrate and for example by sol-gel coating in
operation (B). The binder component shrinks during a curing process
of the formed scattering layer 20, and the uneven structure is
formed by the scattering particles 40 and/or the conductive pattern
30. The planarizing layer 21 is formed on the scattering layer 20
in which the uneven structure is formed using a siloxane binder in
which titanium dioxide is incorporated in operation (C). An organic
electronic element may be stacked on the formed substrate for an
organic electronic element in operation (D). The organic electronic
element may be formed, for example, by stacking a first transparent
electrode 40, an organic layer 50 including an emission layer and a
second electrode 60, in this order.
[0041] Still further, the present invention provides an organic
electronic device including the substrate described above and the
organic electronic element formed on the substrate. Depending on
the situation, a further stacked structure may be included to
increase device characteristics. The structure of stacks on the
substrate for an organic electronic element may be widely varied
and added by those of ordinary skill in the art, and for example,
the organic electronic element may be an organic light emitting
diode. For instance, the organic electronic device may include a
substrate for an organic electronic element; a first transparent
electrode formed on the substrate; an organic layer including at
least one emission layer; and a second electrode, and may further
include a metal line between the first transparent electrode and
the organic electronic element to compensate a voltage drop of the
first transparent electrode.
[0042] FIG. 3 illustrates a schematic diagram showing a stacked
structure of the organic electronic element including the substrate
for an organic electronic element according to an example of the
present invention. Referring to FIG. 3, the organic electronic
element may be constructed by forming a first electrode 40 on the
substrate prepared in FIG. 1, an organic layer 50 including an
emission layer, and a second electrode 60, in this order.
[0043] Hereinafter, exemplary embodiments of the present invention
will be described in detail. However, the present invention is not
limited to the embodiments disclosed below, but may be implemented
in various forms.
EXAMPLES
Example 1
Preparation of Substrate for an Organic Electronic Element
[0044] A coating solution was prepared by sufficiently dispersing 1
g of polymer bead (XX75BQ, 3 .mu.m in diameter, available from
Sekisui) of which a refractive index was about 1.52 in TMOS 10 g
(Si(OCH.sub.3).sub.4, siloxane). An conductive pattern having a
mesh form was formed by a roll printing method using a silver (Ag)
paste on a glass substrate. The prepared coating solution was
applied to the glass substrate on which the conductive pattern is
formed. A scattering layer was formed by curing the applied coating
solution. Further, the substrate for an organic electronic element
in which the planarizing layer was formed was manufactured by
applying and drying an inorganic binder (siloxane), in which a
highly refractive filler (titanium dioxide) was dispersed, on the
scattering layer. In the obtained substrate for an organic
electronic element, the difference of the refractive indexes of the
planarizing layer and the polymer bead was set to be 0.4 by
controlling a content of the highly refractive filler during the
formation of the planarizing layer.
[0045] Manufacture of OLED
[0046] A white OLED having an emission area of 2.times.2 mm.sup.2
was manufactured by stacking a first electrode, an organic layer
and a second electrode, in this order, on the highly refractive
layer of the substrate for an organic electronic element prepared
as described above. For the first electrode, indium tin oxide (ITO)
was used, and for the second electrode, an aluminum (Al) thin layer
was used. Further, the organic layer was structured to include a
hole injection layer, a hole transport layer, an emission layer, an
electron transport layer and an electron injection layer. For each
stacked structure, the generally used materials in the field of
white OLED manufacture were employed, and also, the general method
was adopted for the formation thereof.
Example 2
[0047] The substrate was prepared in the same manner as Example 1,
except that the amount of the scattering particles during the
preparation of the coating solution was changed to 1.5 g, the
difference of refractive indexes of the polymer bead and the
planarizing layer was controlled to be 0.8, and an OLED element was
formed on the obtained substrate.
Example 3
[0048] The substrate was prepared in the same manner as Example 1,
except that TEOS (Si(OC.sub.2H.sub.5).sub.4) was used as the binder
during the manufacture of the substrate for an organic electronic
element, and an OLED element was formed on the obtained
substrate.
Comparative Example 1
[0049] The substrate was prepared in the same manner as Example 1,
except that methyl methacrylate was used instead of the siloxane
during the manufacture of the substrate for an organic electronic
element, the difference of refractive indexes of the planarizing
layer and the polymer bead was controlled to be 0.2, and an OLED
element was formed on the obtained substrate.
Comparative Example 2
[0050] The substrate was prepared in the same manner as Example 1,
except that the difference of refractive indexes of the planarizing
layer and the polymer bead was controlled to be 0.2 during the
manufacture of the substrate for an organic electronic element, the
conductive pattern was not formed, and an OLED element was formed
on the obtained substrate.
Experimental Example 1
Comparison of Light Extraction Efficiency According to Difference
of Refractive Indexes of Scattering Particles and Planarizing
Layer
[0051] A light extraction efficiency was comparatively measured for
the OLED elements prepared in Examples 1 and 2 and Comparative
Example 1. Particularly, each OLED was operated under the constant
current driving condition of 0.4 mA, and the light extraction
efficiency was assessed by measuring a luminous flux of the
extracted light. The results are summarized in Table 1 below. In
Table 1, Na denotes a refractive index of the scattering particles,
Nb denotes a refractive index of the planarizing layer, and N.A.
denotes a case in which the difference of the refractive indexes is
substantially zero.
TABLE-US-00001 TABLE 1 Difference of refractive No. indexes
(|Na--Nb|) Luminous flux (lm) Control group N.A. 0.052 Comparative
Example 1 0.2 0.068 Example 1 0.4 0.075 Example 2 0.8 0.080
Experimental Example 2
Measurement of Surface Resistance of Device
[0052] A surface resistance was measured for the organic electronic
element prepared in Examples 1 and 2 and Comparative Example 1. The
results are summarized in Table 2 below.
TABLE-US-00002 TABLE 2 Example 1 Example 2 Comparative Example 2
Surface resistance 5.1 5.2 38 (.OMEGA./m.sup.2)
[0053] From the results in Table 2, it can be seen that the surface
resistance is drastically decreased in the substrate for an organic
electronic element according to the present invention in which the
conductive pattern is formed, compared with the conventional
substrate.
INDUSTRIAL APPLICABILITY
[0054] The substrate for an organic electronic element according to
the present invention can be used in various organic electronic
devices, including a display device and a lighting device.
* * * * *