The reflectivity and ohmic contact resistivity of Ni/Ag/Ti/Au in contact with p-GaN

被引：5

作者：

Huang Ya-Ping ^{[1
,2
]}

Yun Feng ^{[1
,2
,3
]}

Ding Wen ^{[1
,2
]}

Wang Yue ^{[2
]}

Wang Hong ^{[2
]}

Zhao Yu-Kun ^{[2
]}

Zhang Ye ^{[2
]}

Guo Mao-Feng ^{[2
]}

Hou Xun ^{[1
,2
]}

Liu Shuo ^{[3
]}

机构：

[1] Xi An Jiao Tong Univ, Shaanxi Prov Key Lab Photon & Informat Technol, Key Lab Phys Elect & Devices, Minist Educ, Xian 710049, Peoples R China

[2] Xi An Jiao Tong Univ, Solid State Lighting Engn Res Ctr, Xian 710049, Peoples R China

[3] Shaanxi Supernova Lighting Technol Co Ltd, Xian 710077, Peoples R China

来源：

ACTA PHYSICA SINICA | 2014年 / 63卷 / 12期

基金：

国家高技术研究发展计划(863计划);

关键词：

p-GaN; ohmic contact; reflectivity; rapidly thermal annealing; LIGHT-EMITTING-DIODES; MECHANISM; CRYSTAL;

D O I：

10.7498/aps.63.127302

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The ohmic reflectivity of Ni/Ag/Ti/Au in contact with p-GaN is studied. It is found that under different thickness values of Ni, different annealing temperatures and different annealing atmospheres, the performances of Ni/Ag/Ti/Au electrode are greatly changed. The contact resistivity is measured using the transmission line model. The reflectivity of the electrode is investigated by using a spectrophotometer. The results reveal that the thinner the Ni metal layer, the higher its reflectivity is, in addition, the thickness value of Ni metal has a little influence on contact resistivity. There appears an abrupt decrease in reflectivity of electrode after annealing at a temperature higher than 400 degrees C. It is noticed that the reflectivity decreases more sharply after annealing in oxygen atmosphere than in nitrogen atmosphere. However, annealing in oxygen atmosphere is more helpful to reduce the contact resistivity. The comprehensive evaluations of the contact resistivity and reflectivity indicate that the better performances of Ni (1 nm)/Ag/Ti/Au electrode after rapid annealing in oxygen atmosphere at 400 degrees C are achieved: its contact resistance reaches 5.5 x 10(-3) Omega.cm(2) and reflectivity rises up to 85% at 450 nm. Light emitting diode (LED) of vertical structure is fabricated with an optimal electrode. The LED under an injection current of 350 mA can achieve the following working parameters: the working voltage is 3.2 V, the optical output power is 270 mW, and the electro-optical conversion efficiency is 24%.

引用

页数：8

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