CN102142496A

CN102142496A - Double-layer transparent electrode on P type GaN (gallium nitride)

Info

Publication number: CN102142496A
Application number: CN2011100474771A
Authority: CN
Inventors: 张昊翔; 叶志镇; 吕建国; 江忠永
Original assignee: Hangzhou Silan Azure Co Ltd
Current assignee: Hangzhou Silan Azure Co Ltd
Priority date: 2011-02-28
Filing date: 2011-02-28
Publication date: 2011-08-03

Abstract

The invention discloses a double-layer transparent electrode on P type GaN (gallium nitride) in GaN based LED (Light-Emitting Diode). The transparent electrode is composed of a double-layer structure of an ITO (Indium Tin Oxide) film and a ZnO (Zinc Oxide) based film. The process steps are that: 1, the ITO film is deposited on the P type GaN to be used as a first transparent conducting layer, and the thickness is 1-1000 microns; and 2, the low-resistance ZnO based film is deposited on the first transparent conducting layer to be used as a second transparent conducting layer, and the resistivity is 10-4 to 10-5 ohm cm. The double-layer transparent electrode has the advantages of low resistivity, high light transmittance and good stability, the current is uniformly deposited, and the double-layer electrode can improve the luminous efficiency of the GaN based LED and prolong the service life.

Description

A kind of P type GaN goes up double-deck transparency electrode

Technical field

The present invention relates to electrode, relate in particular to a kind of P type GaN and go up double-deck transparency electrode.

Background technology

The GaN sill is a kind of desirable short-wave long light-emitting device material.Along with the practicability of royal purple light GaN base LED, white light LEDs may replace various traditional illumination light, and lighting technology can welcome a new revolution.But also still there are some technical barriers in the making of GaN base LED at present, goes up the preparation of Ohm contact electrode as P type GaN.Ni/Au is the P type GaN contact electrode of using always, but Ni/Au is opaque, and this has restricted the raising of GaN base LED luminous efficiency.

At present, the LED transparency electrode mainly adopts tin indium oxide (ITO).That ITO has is transparent, the characteristic of conduction, but ITO is difficult to realize the even diffusion of electric current as transparency electrode, and stability is bad.Moreover, whole world In reserves seldom, price is very high, and ITO has toxicity.Thereby, finding a kind of new transparent electrode structure, replacement or part replace ITO, and obtain the ohmic contact of the evenly diffusion of low-resistance, electric current, high transmission rate and high stability on P type GaN, thereby improve the LED luminous efficiency, are the problems that the scientific research personnel pays close attention to always.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, provide a kind of P type GaN to go up double-deck transparency electrode

P type GaN goes up double-deck transparency electrode and comprises P type GaN layer, ito thin film and zno-based film; Be provided with ito thin film and zno-based film in turn on P type GaN layer, ito thin film is first transparency conducting layer, and the zno-based film is second transparency conducting layer.

The thickness of described ito thin film is 1～1000 micron.Described zno-based film is the ZnO film that B, Al, Ga, In, F, Cl, Si, Sn, Zr or Ti mix, and resistivity is 10 ^{– 4}～10 ^{– 5}Ω cm.Described ito thin film and zno-based depositing of thin film method are sputter, evaporation, spraying thermal decomposition or chemical vapour deposition (CVD).

The beneficial effect that the present invention compared with prior art has is:

1) ITO is as first transparency conducting layer, Heat stability is good, and GaN can form good Ohmic contact with the P type;

2) the zno-based film of donor doping is as second transparency conducting layer, the light transmittance height, and chemical stability is good, and ITO first transparency conducting layer is played a protective role;

3) ITO and ZnO interface crystal lattice matching are good, utilize the double-deck transparent electrode structure of ITO and ZnO, can promote electric current evenly to be diffused into electrode surface, improve device performance;

4) the double-deck transparent electrode structure of ITO and ZnO can be realized the requirement of the evenly diffusion of low-resistance, electric current, high transmission rate and high stability, thereby improves luminous efficiency and the life-span of GaN base LED;

5) the double-deck transparent electrode structure of employing ITO and ZnO can partly replace ito thin film, thereby reduces the device material cost, also helps environmental protection.

Description of drawings

Fig. 1 is that P type GaN goes up double-deck transparent electrode structure schematic diagram.

Embodiment

As shown in Figure 1, the last double-deck transparency electrode of P type GaN comprises P type GaN layer 1, ito thin film 2 and zno-based film 3; Be provided with ito thin film 2 and zno-based film 3 in turn on P type GaN layer 1, ito thin film 2 is first transparency conducting layer, and zno-based film 3 is second transparency conducting layer.

The thickness of described ito thin film 2 is 1～1000 micron.Described zno-based film 3 is the ZnO film that B, Al, Ga, In, F, Cl, Si, Sn, Zr or Ti mix, and resistivity is 10 ^{– 4}～10 ^{– 5}Ω cm.

The deposition process of described ito thin film 2 and zno-based film 3 is: sputter, evaporation, spraying thermal decomposition or chemical vapour deposition (CVD).

Embodiment 1:

On P type GaN layer 1, adopt magnetron sputtering technique to deposit successively from bottom to top as the ito thin film 2 of first transparent electrode layer with as the zno-based film 3 of second transparent electrode layer.Adopt P type GaN to go up the GaN base LED of ITO and zno-based two-layer electrode, its luminous efficiency can improve 1 ~ 5%.

Embodiment 2:

On P type GaN layer 1, adopt evaporation technique to deposit successively from bottom to top as the ito thin film 2 of first transparent electrode layer with as the zno-based film 3 of second transparent electrode layer.Adopt P type GaN to go up the GaN base LED of ITO and zno-based two-layer electrode, its luminous efficiency can improve 1 ~ 4%.

Claims

1. a P type GaN goes up double-deck transparency electrode, it is characterized in that comprising P type GaN layer (1), ito thin film (2) and zno-based film (3); Be provided with ito thin film (2) and zno-based film (3) on P type GaN layer (1) in turn, ito thin film (2) is first transparency conducting layer, and zno-based film (3) is second transparency conducting layer.

2. go up double-deck transparency electrode by the described a kind of P type GaN of claim 1, the thickness that it is characterized in that described ito thin film (2) is 1～1000 micron.

3. go up double-deck transparency electrode by the described a kind of P type GaN of claim 1, it is characterized in that the ZnO film that described zno-based film (3) mixes for B, Al, Ga, In, F, Cl, Si, Sn, Zr or Ti, resistivity is 10 ^{– 4}～10 ^{– 5}Ω cm.

4. go up double-deck transparency electrode by the described a kind of P type GaN of claim 1, the deposition process that it is characterized in that described ito thin film (2) and zno-based film (3) is sputter, evaporation, spraying thermal decomposition or chemical vapour deposition (CVD).