KR20170122419A - Reflecting electrode for light emitting diode and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a reflective electrode for a light emitting element and a manufacturing method thereof. More specifically, the present invention relates to a reflective electrode for a light emitting element and a manufacturing method thereof, the reflective electrode comprising an Ag reflective layer formed on a semiconductor layer and having a thickness of 100 nm to 5 m. The Ag reflective layer includes: a first Ag layer; a second Ag layer; and a nanoparticle layer formed between the first Ag layer and the second Ag layer. Provided is an Ag based reflective electrode for a light emitting element, which obtains excellent thermal stability to exhibit a stable reflective property.

Description

TECHNICAL FIELD [0001] The present invention relates to a reflective electrode for a light emitting device, and a method of manufacturing the same. BACKGROUND ART [0002] Reflecting Electrode for Light Emitting Diode &

The present invention relates to a reflective electrode for a light-emitting element, a method of manufacturing the same, and a light-emitting element including the same.

A light emitting diode (LED) has a heterojunction structure of a p-type semiconductor and an n-type semiconductor using a compound semiconductor. When a voltage is applied, electrons and holes combine to emit energy corresponding to a semiconductor band gap in the form of light Lt; / RTI > As light emitting diodes, p-type GaN and n-type GaN, which are nitride semiconductors, are mainly used, and LEDs such as a horizontal structure, a vertical structure, and a flip chip structure are proposed.

The flip chip LED does not require wire bonding, can realize weight reduction and miniaturization, and the bonding pad not only does not interfere with the extraction of light from the active area, but also has a thermal resistance of at least 8 ° C / W .

The LED of the flip chip structure uses an Ag reflective electrode having high reflectance and good contact property with p-type GaN to prevent optical loss in the ohmic metal due to the high surface resistance of p-type-GaN.

In order to realize ohmic contact with the p-type GaN, the Ag reflective electrode requires a heat treatment process at a temperature of 300 ° C or higher. After the heat treatment process, A large amount of pores are generated at the interface of the GaN layer, and as a result, the reflectance decreases. In addition, Ag migration phenomenon due to the low thermal stability of Ag can be a weak point in leakage current.

In order to solve these problems, methods of introducing various processes or new materials at the interface between the p-GaN layer and the Ag reflective electrode have been proposed and some improvements have been made. However, when a new layer is introduced, the reflectance is decreased or the reflectance is not significantly improved have.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a reflective electrode for a light emitting device having excellent heat stability and a high reflectance and a method for manufacturing the same.

The present invention provides a light emitting device including a reflective electrode for a light emitting device according to the present invention.

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

According to one aspect of the present invention,

An Ag reflective layer having a thickness of 100 nm to 5 占 퐉 formed on the semiconductor layer; / RTI >

The Ag reflective layer includes a first Ag layer; A second Ag layer; And a nanoparticle layer formed between the first Ag layer and the second Ag layer; To a reflective electrode for a light-emitting element.

According to an embodiment of the present invention, the nanoparticle layer includes at least one selected from the group consisting of Cu, Ag, Ni, In, Al, Pt, Pb, Ti, Cr, Au, Nanoparticles.

According to an embodiment of the present invention, the nanoparticle layer may include nanoparticles having a diameter of 20 nm or less.

According to an embodiment of the present invention, the thicknesses of the first Ag layer and the second Ag layer are respectively 50 nm to 1 탆, and the thicknesses of the first Ag layer and the second Ag layer are the same Or may be different.

According to another aspect of the present invention,

Preparing a semiconductor layer; Forming a first Ag layer on the semiconductor layer; Wherein the first Ag layer includes at least one material selected from the group consisting of Cu, Ag, Ni, In, Al, Pt, Pb, Ti, Cr, Au, Sn and ITO. Forming a nanoparticle layer comprising nanoparticles having a diameter; And forming a second Ag layer on the nanoparticle layer; The present invention relates to a method of manufacturing a reflective electrode for a light emitting device.

According to an embodiment of the present invention, the method may further include a step of forming a nanoparticle layer, forming a second Ag layer, or performing a heat treatment after the two steps.

According to one embodiment of the present invention, the heat-treating step may be performed at 200 ° C to 700 ° C for 1 minute to 30 minutes.

INDUSTRIAL APPLICABILITY The present invention can provide a reflective electrode for a light-emitting element that prevents agglomeration of the Ag reflective layer during heat treatment and prevents a decrease in reflectance.

In addition, the present invention can provide a reflective electrode for a light emitting device which is improved in thermal stability and can be realized at a high temperature.

In addition, the present invention can improve the performance of the light emitting device by applying the reflective electrode for a light emitting device according to the present invention.

1 is a cross-sectional view illustrating a reflective electrode for a light emitting device according to an embodiment of the present invention.
2A to 2D illustrate a method of manufacturing a reflective electrode for a light emitting device according to an embodiment of the present invention.
3 is a cross-sectional view illustrating a light emitting device including a reflective electrode for a light emitting device according to an embodiment of the present invention.
4 is an SEM image of the surface of the reflective electrode prepared in Example 1 and Comparative Example 1 of the present invention.
5 shows the optical reflectance in the visible light region of the reflective electrode manufactured in Example 1 of the present invention.
6 shows the optical reflectance in the visible light region of the reflective electrode manufactured in Comparative Example 1 of the present invention.
FIG. 7 shows a current-voltage characteristic curve (IV curve) of the reflective electrode manufactured in Example 1 of the present invention.
FIG. 8 shows the optical output-current characteristic curve (LI curve) of the reflective electrode manufactured in Example 1 of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. Also, terminologies used herein are terms used to properly represent preferred embodiments of the present invention, which may vary depending on the user, intent of the operator, or custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification. Like reference symbols in the drawings denote like elements.

The present invention relates to a reflective electrode for a light-emitting device, and a reflective electrode for a light-emitting device according to an embodiment of the present invention has improved thermal stability to provide a high reflectance, An Ag-based reflective electrode that can be improved can be provided.

1 is a cross-sectional view of a reflective electrode for a light emitting device according to an embodiment of the present invention, and FIG. 1 is a cross-sectional view of an exemplary embodiment of a reflective electrode for a light emitting device according to an embodiment of the present invention. . 1, the reflective electrode for a light-emitting element includes an Ag reflective layer 20, and the Ag reflective layer 20 may include an Ag layer and a nanoparticle layer.

In one embodiment of the present invention, the Ag reflective layer 20 reflects light emitted from the semiconductor layer 10 and forms an ohmic contact with the semiconductor layer 10. For example, the Ag reflective layer 20 may have a thickness of 100 nm to 5 占 퐉, preferably 100 nm to 1 占 퐉; More preferably 100 nm to 600 nm. When the thickness of the Ag reflective layer 20 is within the above range, ohmic contact with the semiconductor layer is well performed and a high reflectance can be provided.

According to an embodiment of the present invention, the Ag reflective layer 20 may include a single layer or a plurality of Ag layers and a nanoparticle layer. For example, referring to FIG. 1 (a) the Ag reflective layer 20 in the step a) may include the first Ag layer 21 and the nanoparticle layer 22.

For example, the semiconductor layer 10 includes a semiconductor compound of a light emitting element to which the Ag reflective layer 20 is applied, and forms an ohmic contact with the Ag reflective layer 20. For example, the n- , An active layer, a p-type semiconductor layer, and the like, but will be described more specifically in the following light emitting device.

The first Ag layer 21 has a good contact property with the semiconductor layer 10 so that ohmic contact with the semiconductor layer 10 is well formed and light emitted from the semiconductor layer 10 , For example, a high reflectance for the blue region. For example, the first Ag layer 21 may have a thickness of 50 nm to 1 占 퐉; Preferably 100 nm to 300 nm thick. If the thickness of the first Ag layer 21 is within the above range, ohmic contact with the semiconductor layer 10 can be easily performed and good adhesion with the semiconductor layer 10 can be provided.

The nanoparticle layer 22 is formed on the first Ag layer 21 to prevent the first Ag layer 21 from aggregating during the temperature increase or heat treatment of the semiconductor layer 10, The semiconductor layer 10 is not in direct contact with the first electrode layer 22 and does not interfere with the formation of the ohmic contact of the first Ag layer. Thus, the reliability of the light emitting device can be improved.

For example, the nanoparticle layer 22 may include at least one nanoparticle selected from the group consisting of Cu, Ag, Ni, In, Al, Pt, Pb, Ti, Cr, Au, And preferably Cu and Ni.

For example, when the nanoparticle layer 22 comprises a mixture of two or more nanoparticles, the same molar ratios (mol%) or the molar ratios of the remaining nanoparticles on either basis in the range of 0.1 to 0.9; Preferably in a molar ratio ranging from 0.2 to 0.6.

For example, the nanoparticle layer 22 may have a diameter of 20 nm or less; Preferably 1 nm to 10 nm diameter; More preferably nanoparticles having a diameter of 1 nm to 3 nm. When the diameter of the nanoparticles is within the above range, it is easy to form a thin and uniform thin film on the first Ag layer 21, spinodal decomposition occurs well, and the thermal stability of the first Ag layer 21 is improved The reflection efficiency can be prevented from lowering.

For example, the nanoparticle layer 22 may be a single layer or a plurality of layers, and the plurality of layers may be composed of two or more layers having the same thickness or different components, or two or more layers. For example, Lt; RTI ID = 0.0 > 1 < / RTI > to 100; Preferably in the range of 1 to 50; More preferably in the range of 1 to 25.

For example, the nanoparticle layer 22 may have a thickness between 1 nm and 100 nm; Preferably 1 nm to 50 nm; More preferably from 1 nm to 25 nm. When the thickness of the nanoparticle layer 22 is within the above range, it is possible to prevent an increase in resistance or decrease in adhesion due to the nanoparticle layer and to prevent aggregation, tearing, and the like of the first Ag layer 21.

1 (b), the Ag reflective layer 20 'includes a first Ag layer 21'a, a nanoparticle layer 22' and a second Ag layer 21'a ' can do.

For example, the Ag reflective layer 20 'is formed on the semiconductor layer, and the first Ag layer 21'a and the nanoparticle layer 22' (21) and the nanoparticle layer (22).

 For example, the second Ag layer 21'a 'may be formed on the nanoparticle layer 22' to further improve the reflection efficiency of the reflective electrode.

For example, the thicknesses of the first Ag layer 21'a and the second Ag layer 21'a 'may be the same or different from each other. For example, the first Ag layer 21'a and the second Ag layer 21'a' May be 100 nm to 300 nm thick, and the second Ag layer 21'a 'may be 100 nm to 1 mu m.

1 (c), the Ag reflective layer 20 '' includes a first Ag layer 21 '' a, a first nanoparticle layer 22 '' b, a second Ag layer '' A ') and a second nanoparticle layer 22 " b'. For example, the Ag reflective layer 20 " may be formed on the semiconductor layer and have a thickness of 100 nm to 5 [mu] m. For example, the first Ag layer 21 '' a, the first nanoparticle layer 22 '' b, and the second Ag layer 21 '' a ' The Ag layer 21'a, the nanoparticle layer 22 'and the second Ag layer 21'a'.

For example, the second nanoparticle layer 22 "b 'may be formed on the second Ag layer 21" a' to improve the thermal stability of the second Ag layer 21 "a ' The reflection efficiency can be prevented from lowering. The thickness of the second nanoparticle layer 22 " b 'may be the same as or different from the thickness of the first nanoparticle layer 22 " b.

For example, the reflective electrode for a light emitting device according to the present invention may be applied to a light emitting diode, a laser diode, a solid laser, or the like, It can be applied to a light emitting diode.

The present invention relates to a method of manufacturing a reflective electrode for a light emitting device according to the present invention and a method of manufacturing a reflective electrode for a light emitting device according to an embodiment of the present invention, An Ag-based reflective electrode having reflectance can be provided.

A method of manufacturing a reflective electrode for a light emitting device according to an embodiment of the present invention will be described with reference to FIG. 2. FIG. 2A to FIG. 2D are cross- And a method of manufacturing a reflective electrode according to an embodiment of the present invention. 2A, the manufacturing method includes: preparing a semiconductor layer (S1); Forming an Ag reflective layer (S2); And a heat treatment step (S3); . ≪ / RTI >

For example, the step (S1) of preparing a semiconductor layer is a step of preparing a semiconductor layer 10 for light generation of the light emitting device. For example, the semiconductor layer 10, which is applicable to a light emitting device having a flip chip structure, For example, the semiconductor layer may include an n-type semiconductor layer, an active layer and a p-type semiconductor layer and the like, but will be described more specifically in the following light emitting device.

For example, the step (S1) of preparing the semiconductor layer may use a method applied in the technical field of the present invention, for example, chemical vapor deposition (CVD), physical vapor deposition (PVD) a semiconductor layer may be formed using a vapor phase growth method such as an organic chemical vapor deposition (MBE), a molecular beam epitaxy (MBE), or a hydride vapor phase epitaxy (HVPE), but the present invention is not limited thereto.

The step S2 of forming the Ag reflective layer includes the step of forming the Ag reflective layer 20 on the semiconductor layer 10, for example, the p-type semiconductor layer prepared in the step S1 of preparing the semiconductor layer, For example, forming a first Ag layer (S2a) and forming a nanoparticle layer (S2b) in FIG. 2B; . ≪ / RTI >

For example, in the step S2a of forming the first Ag layer, a first Ag layer 21 is formed on the semiconductor layer 10 to form an ohmic contact with the semiconductor layer 10. The first Ag layer 21 is constituted by the above-mentioned reflective electrode.

For example, the step S2a of forming the first Ag layer may be performed by a sputtering method such as DC magnetron sputtering or radio frequency magnetron sputtering, an evaporation deposition method, a chemical vapor deposition (CVD) method, a thermochemical vapor deposition (TCVD) A microwave plasma chemical vapor deposition (MPECVD) method, a solution deposition method, or the like can be used, and the first Ag layer 21 can be formed by evaporation deposition method.

For example, the step S2b of forming the nanoparticle layer is a step of forming the nanoparticle layer 22 on the first Ag layer 21 after the step S2a of forming the first Ag layer. The nanoparticle layer 22 is composed of the above-mentioned reflective electrode. The step S2b of forming the nanoparticle layer may be performed by a sputtering method such as DC magnetron sputtering or radio frequency magnetron sputtering, an E-Beam deposition method, a chemical vapor deposition method (CVD), a thermo-chemical vapor deposition method (TCVD), a vapor deposition method, The nanoparticle layer 22 can be formed by vapor deposition (MPECVD), solution deposition, spin coating, inkjet coating, or the like.

In an example of the present invention, the step S2 'of forming the Ag reflective layer in FIG. 2 (c) includes the steps of forming the first Ag layer (S2'a), forming the nanoparticle layer (S2'b) And forming a second Ag layer (S2'a ').

For example, the step of forming the first Ag layer (S2'a) and the step of forming the nanoparticle layer (S2'b) are performed in the same manner as the step of forming the Ag reflective layer (S2).

For example, the step of forming a second Ag layer (S2'a ') may include forming a second Ag layer (21'a') on the nanoparticle layer (22 ') after forming the nanoparticle layer (S2'b) ). The step (S2'a ') of forming the second Ag layer is performed in the same manner as the step (S2'a) of forming the first Ag layer.

2 (d), the step (S2 '') of forming the Ag reflective layer includes the steps of forming the first Ag layer (S2 '' a), forming the first nanoparticle layer (step S2 'b) forming a second Ag layer (S2' 'a') and forming a second nanoparticle layer (S2 '' b '); . ≪ / RTI >

For example, the step of forming the first Ag layer (S2 '' a), the step of forming the first nanoparticle layer (S2 '' b) and the step of forming the second Ag layer (S2 '' a ' , And step (S2 ') of forming an Ag reflective layer.

For example, the step (S2''b ') of forming the second nanoparticle layer may be performed on the second Ag layer 21''a' after the step (S2''a ') of forming the second Ag layer Is a step of forming a second nanoparticle layer 22 " b ', and is performed in the same manner as the step (S2 " b) of forming the first nanoparticle layer.

In an exemplary embodiment of the present invention, the step of heat-treating (S3) is a step of forming an ohmic contact with the semiconductor layer 10 by heat-treating the Ag reflective layers 20, 20 'and 20''after the step (S2) . For example, the heat treatment step S3 may be performed in an air atmosphere or an O ₂ atmosphere at a temperature of 200 ° C to 700 ° C for 30 seconds to 1 hour, preferably 1 minute to 30 minutes, more preferably 30 seconds to 5 minutes Lt; / RTI > Each layer of the thin film type deposited by heat treatment after the formation of the Ag reflective layer is deformed into a particle shape and if it is contained within the above range of the heat treatment temperature and the time range, ohmic contact with the semiconductor layer is well performed, have.

In another example of the present invention, the heat-treating step (S3) may be carried out after the formation of the respective layers constituting the Ag reflective layer. For example, the step (S2'b ), Forming a second Ag layer (S2'a ') or both, and forming a first nanoparticle layer (S2''b) in FIG. 2 (d) The step (S2 '' a ') of forming the Ag layer and the step (S2' 'b') of forming the second nanoparticle layer, and the heat treatment conditions are as described above.

The present invention relates to a light emitting device, and a light emitting device according to an embodiment of the present invention can improve reliability and performance by applying a reflective electrode having a high reflectance and excellent thermal stability during a heat treatment at a high temperature.

3 is a cross-sectional view illustrating a light emitting device according to an embodiment of the present invention. Referring to FIG. 3, a light emitting device according to an embodiment of the present invention will be described with reference to FIG.

3, the light emitting device is a light emitting device having a flip chip structure, and includes a zener diode 110, a solder bumper 120, a reflective electrode layer 130, a semiconductor layer 140, and a substrate (not shown) 150). For example, a solder bumper 120, a reflective electrode layer 130, a semiconductor layer 140, and a substrate 150 are sequentially formed on at least a portion of a zener diode 110.

In an exemplary embodiment of the present invention, a zener diode (110) serves as a support for a light emitting device. When a voltage is applied in a direction opposite to the positive direction, a pn junction is formed. For example, a zener diode 160 is formed by bonding a p-type substrate and an n-type substrate, and the p-type substrate includes any one of Si, Ge, InP, SiC, GaAs, Type substrate may include any one of Si, Ge, InP, SiC, GaAs, and GaN.

The solder bumper 120 is for electrically connecting the light emitting device to the zener diode 110. For example, the solder bumper 120 may be made of nickel, copper, palladium, platinum , Tin, lead, gold, silver, copper, and bismuth. For example, the sorb bumper 120 may be configured in various shapes, and may be a structure having an elliptical shape, a circular shape, a concave shape, a cylindrical shape, a polygonal column, or the like.

In one embodiment of the present invention, the reflective electrode layer 130 includes a reflective electrode including an Ag reflective layer according to the present invention. The reflective electrode layer 130 forms ohmic contact with the semiconductor layer 140, for example, the p-type semiconductor layer, and reflects light emitted from the semiconductor layer 140.

Since the reflective electrode layer 130 according to the present invention is applied to the reflective electrode layer 130, the reflectivity of the reflective electrode layer 130 is high and the ohmic contact with the Ag layer is performed well, thereby improving the reliability and output of the light emitting device.

The semiconductor layer 140 may include a first semiconductor layer 141, an active layer 142, and a second semiconductor layer 143.

For example, the first semiconductor layer 141 may be a III-V semiconductor compound, a II-VI semiconductor compound, or a p-type semiconductor compound containing both of them. For example, the III-V semiconductor compound may be at least one selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, AlGaN, AlGaP, AlGaAs, AlGaSb, InGaN, GaInP, GaInAs ZnS, ZnTe, CdS, CdSe, ZnSe, ZnTe, ZnSe, ZnTe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, ZnSe, AlInN, And CdTe. ≪ / RTI >

For example, the active layer 142 is a region where light is generated, and may include a single or multiple quantum well layer. The active layer 142 includes a III-V semiconductor compound and may be formed of a material such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, AlGaN, AlGaP, AlGaSb, InGaN, GaInP, GaInAs, GaInSb, AlInN, AlInP, AlInAs, AlInSb, AlGaInN, AlGaInP, AlGaInAs and AlGaInSb. The multiple quantum structure may include AlN / AlGaN, AlN / GaN, AlN / InGaN, AlN / InN, AlN / AlGaInN, AlGaN / InGaN, AlGaN / AlGaInN, GaN / InGaN, GaN / InN, AlGaInN / InGaN, AlGaInN / InN, AlP / And may include at least one selected from the group consisting of AlP / InGaP, AlP / InP, AlP / AlGaInP, AlGaP / GaP, and AlGaP / InGaP.

For example, the second semiconductor layer 143 may be an III-V semiconductor compound, an II-VI semiconductor compound, or an n-type semiconductor compound containing both of them. For example, the III-V semiconductor compound may be one selected from the group consisting of GaN, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, AlGaN, AlGaP, AlGaAs, AlGaSb, InGaN, GaInP, GaInAs, GaInSb ZnS, ZnTe, CdS, CdSe, and ZnSe, wherein the II-VI based semiconductor compound contains at least one element selected from the group consisting of AlN, AlInP, CdTe, and the like.

The light emitting device may further include an electrode 160 to supply electric current to the light emitting device to enable electric driving. For example, the light emitting device may include an n-type electrode and a p- And can be appropriately disposed for electric driving of the light emitting element. For example, the n-type electrode may be formed of a metal such as Co, Ir, Ta, Cr, Mn, Mo, Tc, W, Re, Fe, Sc, Ti, Sn, Ge, Sb, Al, Pt, Or a mixture of two or more of them. For example, the p-type electrode may be formed of Co, Ir, Ta, Cr, Mn, Mo, Tc, W, Re, Fe, Sc, Ti, Sn, Ge, Sb, Al, Pt, Ni, Au, Or a mixture of two or more of them.

In an embodiment of the present invention, the light emitting device may further include a configuration applied in the technical field of the present invention depending on the use of the light emitting device, etc., and is not specifically described herein.

It will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the following claims And changes may be made without departing from the spirit and scope of the invention.

Example  One

(150 nm) / NiCu (Ni: Cu layer = 2 nm: 50 nm) / Ag (150 nm) / NiCu (Ni: Cu = 2 nm: 50 nm, mixing ratio Ni: Cu = 2: 1) After evaporation in the order of evaporator, the films were annealed in the order of 300 ° C, 400 ° C, 500 ° C, and 600 ° C in an O ₂ atmosphere for 1 minute to fabricate a reflective electrode. SEM image and optical reflectance (UV-VIS spectrometer, Varian 300 Bio) of the surface of the prepared reflection electrode were measured and shown in Fig. 4 (a) and Fig. The current-voltage characteristic curve (IV curve) and the light output-current characteristic curve (LI curve) of the manufactured reflection electrode were measured and shown in FIG. 7 and FIG.

Comparative Example  One

Ag (150 nm) was evaporated on a p-type GaN substrate by an evaporator, and then annealed in an O ₂ atmosphere for 1 minute in order of 300 ° C, 400 ° C, 500 ° C, and 600 ° C, respectively. The SEM image and the light reflectance (UV-VIS spectrometer) of the surface of the prepared reflection electrode were measured and shown in FIG. 4 (b) and FIG.

4 and FIG. 6, in the Ag reflective electrode (Example 1) in which the nanoparticle layer according to the present invention was formed in FIGS. 4 and 6, the coagulation phenomenon of the film hardly occurred compared with Comparative Example 1 in heat treatment, Of Comparative Example 1 was significantly lower than that of Comparative Example 1.

In FIGS. 7 and 8, it can be seen that the reflective electrode of Example 1 exhibits excellent results in current-voltage characteristic curves (IV curve) and optical output-current characteristic curves (LI curve) at 500 ° C. .

The present invention provides a light emitting device having a high brightness and an improved output by applying a multi-layered Ag reflective electrode including a nanoparticle layer on the Ag layer to improve not only the thermal stability of the Ag reflective electrode but also the decrease in reflectance .

Claims (5)

An Ag reflective layer having a thickness of 100 nm to 5 占 퐉 formed on the semiconductor layer; / RTI >
The Ag reflective layer includes a first Ag layer; A second Ag layer; And a nanoparticle layer formed between the first Ag layer and the second Ag layer; And a reflective electrode formed on the reflective electrode.
The method according to claim 1,
Wherein the nanoparticle layer comprises nanoparticles comprising at least one material selected from the group consisting of Cu, Ag, Ni, In, Al, Pt, Pb, Ti, Cr, Au, Sn and ITO. Reflective electrode for device.
The method according to claim 1,
Wherein the nanoparticle layer comprises nanoparticles having a diameter of 20 nm or less.
The method according to claim 1,
The thicknesses of the first Ag layer and the second Ag layer are each 50 nm to 1 탆 or less,
Wherein the thickness of the first Ag layer and the thickness of the second Ag layer are the same or different from each other.
Preparing a semiconductor layer;
Forming a first Ag layer on the semiconductor layer;
A nanoparticle layer containing nanoparticles having a diameter of 20 nm or less and containing at least one substance selected from the group consisting of Cu, Ag, Ni, In, Ga, Pt and Pd on the first Ag layer. ; And
Forming a second Ag layer on the nanoparticle layer;
Wherein the reflective electrode is formed of a transparent conductive material.

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