KR101780893B1 - Electro luminescence device included in lighting apparatus and method of manufacturing the same - Google Patents

Abstract

The present invention relates to an electroluminescent device in which a light emitting layer is uniformly formed and light emission uniformity is improved, and a method of manufacturing the same.
An electroluminescent device according to an embodiment of the present invention includes a substrate on which a plurality of trenches are formed on one surface; An auxiliary electrode inserted in the trench and configured such that an upper portion is disposed lower than the one surface; A first electrode covering the auxiliary electrode and stacked on the one surface to form a recessed portion in a region corresponding to the auxiliary electrode; An insulator inserted in the recess portion and stacked on the first electrode; A light emitting layer laminated on the first electrode and the insulator; And a second electrode stacked on the light emitting layer; And a control unit.
According to the electroluminescent device of the present invention and the method of manufacturing the same, a uniform luminescent layer can be formed by etching the substrate and inserting the auxiliary electrode. Furthermore, since a uniform light emitting layer is formed, the current crowding phenomenon in the light emitting layer is improved, and the light emitting uniformity can be improved.

Description

TECHNICAL FIELD [0001] The present invention relates to an electroluminescent device and a method of manufacturing the electroluminescent device,

The present invention relates to an electroluminescent device included in a lighting device and a method of manufacturing the electroluminescent device, and more specifically, to an electroluminescent device having uniformly formed light emitting layers to improve luminous uniformity and a method of manufacturing the same.

2. Description of the Related Art Generally, an electro luminescence device is a device in which holes supplied from an anode and electrons supplied from a cathode are combined in a light emitting layer formed between an anode and a cathode to emit light . Such an electroluminescent device is attracting attention as a next generation flat panel display (FPD) because it exhibits excellent display characteristics such as wide viewing angle, fast response speed, thin thickness, low manufacturing cost and high contrast.

Such an electroluminescent device can be divided into a passive matrix electroluminescent device and an active matrix electroluminescent device according to a driving method. In particular, a passive matrix electroluminescent device is a simple structure in which an anode and a cathode are arranged in a matrix and emits light in a light emitting layer between an anode and a cathode, and is widely used as a surface light source of an illumination device.

On the other hand, at least one of the anode and the cathode of the electroluminescent element is formed of a transparent conducting oxide (TCO) so as to transmit light. Although such a transparent conductive oxide is advantageous in transparency compared to a general metal, it has a problem that a voltage drop phenomenon occurs in an electrode formed of a conductive oxide because of its high resistivity. As the electroluminescent device is manufactured in a large area, the voltage drop phenomenon at the electrode becomes large, and the luminance of the illumination device is high at the injection portion where the current is injected. However, the brightness deviation is relatively decreased as the distance from the injection portion is increased do.

In order to solve such a problem, a method of improving the electrical conductivity of an electrode formed of a conductive oxide by contacting an auxiliary electrode having a relatively low specific resistance to an electrode formed of a conductive oxide is mainly used.

1 is a schematic cross-sectional view of an electroluminescent device included in a conventional electroluminescent lighting device.

1, a conventional electroluminescent element 1 includes a substrate 2, a positive electrode 3 formed on one surface of the substrate 2, an auxiliary electrode 4 contacting the positive electrode 3, an auxiliary electrode 4 The light emitting layer 6 and the cathode 7 formed on the insulator 5, the anode 3 and the insulator 5, The electroluminescent element 1 may include the auxiliary electrode 4 to improve the electrical conductivity of the anode 3.

However, in the conventional electroluminescent element 1, the auxiliary electrode 4 is arranged so as to protrude on the anode 3, and the luminous layer 6 in the luminous region EA (in particular, the region adjacent to the auxiliary electrode) There is a limitation that it can not be uniformly formed. When current is applied to the non-uniform light emitting layer 6, a current flow occurs, resulting in a problem that the uniformity of light emission of the electroluminescent element 1 is lowered.

1. Korean Patent Laid-Open No. 10-2013-0033093 (entitled " Organic Electroluminescent Device and Manufacturing Method Therefor) 2. Korean Patent Publication No. 10-2013-0033100 (entitled OLED)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electroluminescent device and a method of manufacturing the electroluminescent device which are uniformly formed with a light emitting layer to improve current mobility and luminous uniformity.

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided an electroluminescent device including: a substrate having a plurality of trenches formed on one surface thereof; An auxiliary electrode inserted in the trench and configured such that an upper portion is disposed lower than the one surface; A first electrode covering the auxiliary electrode and stacked on the one surface to form a recess in a region corresponding to the opening of the trench; An insulator inserted in the recess portion and stacked on the first electrode; A light emitting layer laminated on the first electrode and the insulator; And a second electrode stacked on the light emitting layer; And a control unit.

According to another aspect of the present invention, the first electrode is a transparent anode, the second electrode is a cathode, and is formed to cover the entire surface of the light emitting layer, Can be reflected.

According to still another aspect of the present invention, the light emitting layer may include a quantum dot.

According to an aspect of the present invention, there is provided a method of manufacturing an electroluminescent device, including: forming a plurality of trenches on a surface of a substrate;

Inserting an auxiliary electrode in the trench so that the top is disposed lower than the one surface; Stacking a first electrode on the one surface to cover the auxiliary electrode and form a recess in a region corresponding to the opening of the trench; Stacking an insulator on the first electrode to be inserted into the recessed portion; Laminating a light emitting layer on the first electrode and the insulator; Stacking a second electrode on the light emitting layer; And a control unit.

According to the electroluminescent device of the present invention and the method of manufacturing the same, a uniform luminescent layer can be formed by etching the substrate and inserting the auxiliary electrode. Furthermore, since a uniform light emitting layer is formed, the current crowding phenomenon in the light emitting layer is improved, and the light emitting uniformity can be improved.

1 is a schematic cross-sectional view of a conventional electroluminescent device.
2 is a schematic plan view of an electroluminescent device according to an embodiment of the present invention.
3 is a schematic cross-sectional view taken along line AA 'of FIG. 2;
4 is a schematic enlarged cross-sectional view of the region B in Fig.
5 is a flowchart illustrating a method of manufacturing an electroluminescent device according to an embodiment of the present invention.
Fig. 6 is a schematic cross-sectional view showing a state in which each step of the manufacturing method of Fig. 4 is completed.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

It is to be understood that elements or layers are referred to as being "on " other elements or layers, including both intervening layers or other elements directly on or in between.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

Like reference numerals refer to like elements throughout the specification.

The sizes and thicknesses of the individual components shown in the figures are shown for convenience of explanation and the present invention is not necessarily limited to the size and thickness of the components shown.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other partially or entirely and technically various interlocking and driving is possible as will be appreciated by those skilled in the art, It may be possible to cooperate with each other in association.

Hereinafter, an electroluminescent device according to an embodiment of the present invention will be described with reference to FIGS. 2 to 4. FIG.

FIG. 2 is a schematic plan view of an electroluminescent device according to an embodiment of the present invention, FIG. 3 is a schematic cross-sectional view taken along AA 'line in FIG. 2, and FIG. 4 is a schematic enlargement Sectional view.

2 and 3, an electroluminescent device 100 according to the present invention includes a substrate 110 having a trench 112 formed on one surface 111, an auxiliary electrode 120 inserted into the trench 112, A light emitting layer 150 and a second electrode 160. The first electrode 130, the insulator 140, the light emitting layer 150, and the second electrode 160 are sequentially stacked on the first electrode 110.

The substrate 110 is a light-transmissive plate for supporting various components of the electroluminescent device 100. The substrate 110 is preferably made to have a light transmittance of 70% or more so as to transmit light emitted from the light emitting layer 150 to be described later.

The substrate 110 may be a glass-based substrate such as glass, sapphire, or quartz. The substrate 110 may be a plastic substrate such as polyimide (PI) having excellent heat resistance, or may be a silicon substrate or a gallium nitride GaN) wafer. The substrate 110 is not limited to the illustrated example, and any substrate known in the art may be used.

The thickness of the substrate 110 can be variously set depending on the material, processing method, application, and the like.

On the other hand, the substrate 110 has a plurality of trenches 112 formed on one surface 111 thereof.

Referring to FIGS. 2 and 3, the trenches 112 are arranged in at least one of a lateral direction and a longitudinal direction of the substrate 110.

The trench 112 is preferably formed to have a depth of less than 50% relative to the thickness of the substrate 110. If the trench 112 is formed at a depth of 50% or more as compared with the thickness of the substrate 110, the substrate 110 may easily break or be damaged along the trench 112. In addition, the slope of the sidewall of the trench 112 may be greater than 10 degrees and less than 60 degrees.

It goes without saying that the depth of the trench 112 and the inclination of the sidewalls can be determined comprehensively according to the design specifications of the electroluminescent element 100.

The auxiliary electrode 120 is arranged to be completely inserted into the trench 112 of the substrate 110. That is, the auxiliary electrode 120 is inserted into the trench 112, and the upper portion of the auxiliary electrode 120 is arranged lower than one surface 111 of the substrate 110.

The auxiliary electrode 120 is electrically connected to the first electrode 130 to be described later to improve electrical characteristics such as electrical conductivity of the first electrode 130. Specifically, the first electrode 130 is brought into contact with the first electrode 130 having a high resistivity, thereby preventing a voltage drop at the first electrode 130. Therefore, even if the electroluminescent element 100 is formed in a large area, the auxiliary electrode 120 can make the current flowing through the first electrode 130 uniform as a whole.

The auxiliary electrode 120 is preferably made of a conductive material having a low specific resistance. Illustratively, the auxiliary electrode 120 may be made of a metal such as lithium (Li), calcium (Ca), aluminum (Al), silver (Ag), magnesium (Mg), gold (Au) / Calcium (LiF / Ca), lithium fluoride / aluminum (LiF / Al).

Meanwhile, it is preferable that the auxiliary electrode 120 is arranged to occupy 15% or less of the area of the electroluminescent element 100. Since the auxiliary electrode 120 is a metal having no light transmitting property, if the area occupied by the auxiliary electrode 120 is 15% or more, the effective light emitting area in which the electroluminescent device 100 actually emits light becomes small, There is a concern.

The first electrode 130 may be an anode that provides holes to the light emitting layer 140 to be described later.

The first electrode 130 is stacked on one surface 111 of the substrate 110 while covering the auxiliary electrode 120 and filling a part of the trench 112.

The first electrode 130 is stacked on one surface 111 of the substrate 110 while forming a recessed portion 131 in a region corresponding to the opening of the trench 112. The first electrode 130 may be formed on one surface 111 of the substrate 110 on which the trench 112 is formed, The first electrode 130 is formed with a recess 131 in a region corresponding to the opening of the trench 112. [

The first electrode 130 is electrically connected to the auxiliary electrode 120 while being in contact with the auxiliary electrode 120. The first electrode 130 transmits light emitted from the light emitting layer 150, which will be described later. The first electrode 130 is preferably formed of a transparent conductive oxide (TCO).

Illustratively, the transparent conductive oxide may be indium tin oxide (ITO) or indium zinc oxide (IZO).

The first electrodes 130 may be formed to have a predetermined width and extend in the lateral direction or the longitudinal direction of the substrate 110 and may be arranged in a grid shape arranged in the lateral direction and the longitudinal direction of the substrate 110 . In addition, it is needless to say that the arrangement and spacing of the first electrodes 130 can be adjusted according to design specifications such as the shape and size of the electroluminescent element 100.

The insulator 140 is disposed in the recess 131 of the first electrode 130 corresponding to the opening of the trench 112 so that the first electrode 130 and the second electrode 160, prevent.

The electroluminescent element 100 can be divided into a plurality of light emitting regions EA and non-light emitting regions N by the insulator 140. [ 2 and 3, the insulator 140 is disposed at a position corresponding to the opening of the trench 112, so that the non-emission region N is formed in the region corresponding to the opening of the trench 112 And the luminescent region EA can be formed in a part of the lattice space defined by the arrangement of the trenches 112. [

Further, the insulator 140 is laminated so as to be completely inserted into the recess 131 of the first electrode 130. The insulator 140 must be completely inserted into the recess 131 of the first electrode 130 so that the light emitting layer 150 is formed at least in a uniform layer in the light emitting region EA. The fact that the insulator 140 is completely inserted here means that the height of the insulator 140 is equal to or smaller than the height of the recess portion 131 so that the upper portion of the insulator 140 is connected to the first electrode 130 located around the recess portion 131, Quot; lower "

The insulator 140 may be made of various materials that enable electrical insulation. Illustratively, the insulator 140 may be silicon oxide (SiOx), silicon nitride (SiNx), aluminum oxide (AlOx), or the like.

The light emitting layer 150 is stacked on the first electrode 130 and the insulator 140 to cover the first electrode 130 and the insulator 140.

The region of the light emitting layer 150 that is in contact with the insulator 140 is electrically insulated from the first electrode 130 to emit light (i.e., the non-light emitting region N) The region of the light emitting layer 150 receives holes and electrons from the first electrode 130 and a second electrode 160 to be described later to emit light (i.e., the light emitting region EA).

As shown in FIG. 3, the light emitting layer 150 may be formed so that a region included in the light emitting region EA is higher than a region included in the non-light emitting region N. This can be achieved by disposing the insulating layer 140 completely inserted in the recess portion 131 as described above. In addition, when the light emitting layer is formed by a spin coating method by forming the region included in the light emitting region EA higher than the region included in the non-light emitting region N, (150) can be uniformly formed.

The electroluminescent device 100 according to the present invention may include a uniform luminescent layer 150 in at least the luminescent region EA so that the electroluminescent device 100 of the present invention can be applied to the conventional electroluminescent device 1), the problem that the current uniformity in the light emitting layer 6 is lowered due to the current crowding phenomenon can be solved.

On the other hand, the light emitting layer 150 includes quantum dots. The quantum dot is an electro-luminescent nano semiconductor particle, and is a luminescent material capable of emitting light of a specific wavelength depending on the size and shape of a quantum dot.

The light emitting layer 150 can emit white light in the light emitting layer 150 by appropriately combining these quantum dots. For example, the emissive layer 150 may include a quantum dot emitting blue light in a wavelength range between about 430 nm and about 470 nm, a quantum dot emitting green light in a wavelength range between about 520 nm and about 560 nm, And the quantum dots emitting red light in the wavelength band between the emission layers 150, the emission layers 150 may emit white light in which they are mixed.

The quantum dot included in the light emitting layer 150 may be a group II-VI, III-V, IV-VI, or IV semiconductor material or a compound thereof on the periodic table. For example, the quantum dot may be CdS, CdSe, GaN, GaP, InN, PbS, Si, Ge, SiC, SiGe or a combination thereof. Further, the quantum dot included in the light emitting layer 150 is not limited to those described above, and may be any semiconductor material or compound known to those skilled in the art.

Meanwhile, the light emitting layer 150 may include only quantum dots, or may include quantum dots and organic materials. Illustratively, the light emitting layer 150 may be formed as a multi-layer structure in which a quantum dot layer 151 and organic layers 152 and 153 are stacked, as shown in FIG. However, it is needless to say that the light emitting layer 150 is not limited to the above, but can be formed by various known methods.

The second electrode 160 may be a cathode that provides electrons to the light emitting layer 150.

The second electrode 160 may be stacked on the light emitting layer 150 to reflect light emitted from the light emitting layer 150 while covering the entire surface of the light emitting layer 150. That is, the second electrode 160 is electrically connected to the first electrode 130 and the light emitting layer 150, and the first electrode 130 and the substrate 110, which are transparent to light emitted from the light emitting layer 150, It changes the path of light so that it can be emitted.

The second electrode 160 may be formed of a metal such as Al, Ag, Ca, Mg, Au, Mo, Ir, Cr, Ti, or Pd or an alloy thereof. However, the present invention is not limited thereto, and it may be made of various known conductive materials. The thickness of the second electrode 160 may be adjusted according to design specifications such as the shape and size of the electroluminescent device 100.

Hereinafter, a method of manufacturing an electroluminescent device according to an embodiment of the present invention will be described with reference to FIGS. 5 and 6 attached hereto.

The structure and the like of the electroluminescent device 100 of the present invention has been described with reference to FIGS. 2 to 4. Therefore, the following description will focus on the step and method of manufacturing the electroluminescent device 100. FIG.

FIG. 5 is a flow chart for explaining a method of manufacturing an electroluminescent device according to an embodiment of the present invention, and FIG. 6 is a schematic cross-sectional view showing a state in which each step of the manufacturing method of FIG. 4 is completed.

Referring to FIG. 5, a method of manufacturing an electroluminescent device according to an embodiment of the present invention includes forming a trench in a substrate S110, inserting an auxiliary electrode into the trench S120, A step (S130) of laminating a first electrode on the substrate and the auxiliary electrode so as to form a part of the light emitting layer, a step (S140) of laminating an insulator to be inserted into the recessed part of the first electrode, (S150), and stacking the second electrode on the light emitting layer (S160).

First, as shown in FIG. 6A, a plurality of trenches 112 are formed on one surface 111 of the substrate 110 (S110).

The method of forming the trenches 112 on the substrate 110 may include a method of physically etching the substrate 110 using a short pulse laser or the like and a chemical method such as dry etchihg or wet etching . However, the present invention is not limited to this, and the present step S110 may be achieved by a known method for forming the trench 112 in the substrate 110.

6B, the auxiliary electrode 120 is inserted into the trench 112 (S120). At this time, the auxiliary electrode 120 is completely inserted into the trench 112 such that the upper portion of the auxiliary electrode 120 is disposed lower than the one surface 111 of the substrate 110.

In this step S120, a liquid conductive material may be added to the trench 112 to cure the conductive material. Alternatively, an electroplating method, a physical vapor deposition method, a chemical vapor deposition method, And may be carried out through various known methods such as sol-gel method.

Next, as shown in FIG. 6C, the first electrode 130 is formed on one surface 111 of the substrate 110 so as to cover the auxiliary electrode 120 (S130).

This step S130 may be performed by various methods such as physical vapor deposition or chemical vapor deposition, sputtering, ion plating, and E-beam evaporation.

The first electrode 130 may have a substantially uniform thickness and may be formed on one surface 111 of the substrate 110 on which the trench 112 is formed, As shown in FIG. The first electrode 130 may be formed to include the recess 131 recessed toward the trench 112 in the region corresponding to the opening of the trench 112. In this case,

If necessary, a step of improving the surface roughness of the first electrode 130 by performing a polishing process after forming the first electrode 130 may be further performed in step S130, and nitric acid, sulfuric acid A step of cleaning the first electrode 130 using an acidic solution such as hydrochloric acid may be further performed to remove impurities remaining on the surface of the first electrode 130.

6D, the insulator 140 is stacked on the recess 131 of the first electrode 130 (S140). At this time, the insulator 140 should be disposed so as to be completely inserted into the recess 131 of the first electrode 130 as described above.

In this step S140, a metal oxide layer is formed on the first electrode layer 130 through sputtering or chemical vapor deposition to form the insulating layer 140 only on the recessed portion 131, a method of patterning and removing the metal oxide layer included in the light emitting region EA by a photolithograph method. Photolithography methods may involve additional processes such as application, exposure, development, etch, and photoresist removal. However, this is merely an example, and various known methods can be used as a method of forming the insulating layer 140.

6E, the light emitting layer 150 is formed to cover the first electrode 130 and the insulator 140 (S150).

This step (S150) can be performed by a spin coating method. The light emitting layer 150 formed on at least the first electrode 130 in this step S150 may be formed by a spin coating method such as a spin coating method in which the insulator 140 is completely inserted into the recess portion 131 in the previous step S140. Can be uniformly stacked.

Next, as shown in FIG. 6F, the second electrode 160 is laminated on the light emitting layer 150 (S160).

This step S160 may be performed in the same manner as the above-described method of forming the first electrode 130 in the step of stacking the first electrode 130 (S130), and thus a detailed description thereof will be omitted.

According to the electroluminescent device and the method of manufacturing the same, a uniform light emitting layer can be formed by etching the substrate and inserting the auxiliary electrode. Furthermore, since a uniform light emitting layer is formed, the current crowding phenomenon in the light emitting layer is improved, and the light emitting uniformity can be improved.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

100 ... Electroluminescent element
110 ... Board
111 ... One side
112 ... Trench
120 ... Auxiliary electrode
130 ... The first electrode
131 ... Recessed part
140 ... Insulator
150 ... The light-
151 ... Quantum dot layer
152, 153 ... Organic layer
160 ... The second electrode

Claims (4)

A substrate on which a plurality of trenches are formed;
An auxiliary electrode inserted in the trench and configured such that an upper portion is disposed lower than the one surface;
A first electrode covering the auxiliary electrode and stacked on the one surface to form a recess in a region corresponding to the opening of the trench;
An insulator inserted in the recess portion and stacked on the first electrode to define a light emitting region and a non-light emitting region;
A light emitting layer laminated on the first electrode and the insulator; And
A second electrode stacked on the light emitting layer; And a second electrode. The method according to claim 1,
The first electrode is a transparent anode,
Wherein the second electrode is a cathode and is formed to cover a front surface of the light emitting layer to reflect light emitted from the light emitting layer. The method according to claim 1,
Wherein the light emitting layer comprises a quantum dot. Forming a plurality of trenches on one surface of the substrate;
Inserting an auxiliary electrode in the trench so that the top is disposed lower than the one surface;
Stacking a first electrode on the one surface to cover the auxiliary electrode and form a recess in a region corresponding to the opening of the trench;
Laminating an insulator defining a light emitting region and a non-luminescent region on the first electrode so as to be inserted into the recess portion;
Laminating a light emitting layer on the first electrode and the insulator; And
Stacking a second electrode on the light emitting layer; And forming a second electrode on the second electrode.

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