GaN/Si-NPA异质结中的点缺陷及其光电特性调控  

The Point Defect and Optoelectronic Property Control of GaN/Si-NPA Heterojunction

作　　者：李新建[1,2] 段丙新[1] LI Xinjian;DUAN Bingxin(School of Physics, Zhengzhou University, Zhengzhou 450001, China;Key Laboratory of Materials Physics of Ministry of Education, Zhengzhou 450001, China)

机构地区：[1]郑州大学物理学院,河南郑州450001 [2]材料物理教育部重点实验室,河南郑州450001

出　　处：《郑州大学学报（理学版）》2021年第2期111-116,共6页Journal of Zhengzhou University:Natural Science Edition

基　　金：国家自然科学基金项目(11974016)。

摘　　要：以硅纳米孔柱阵列(Si-NPA)为功能性衬底,采用化学气相沉积法制备了GaN/Si-NPA异质结。实验发现,在富镓条件下GaN生长过程中容易引入镓空位和氮间隙等点缺陷,从而对异质结的发光及电学特性产生不良影响。在氨气氛围中进行高温退火后,GaN/Si-NPA的光致发光谱发生明显变化,对应于缺陷发光的黄光发光峰强度和半高宽明显减小,反映出GaN中点缺陷种类和浓度均显著减少。进一步的电学性能测试结果显示,GaN/Si-NPA异质结在退火前后均具有整流效应,但退火后异质结的漏电流密度显著减小,开启电压、正向电流密度、反向截止电压和整流比均有所增加。通过对GaN/Si-NPA异质结在氨气氛围中进行高温退火,可以实现对其点缺陷种类和浓度的有效调控。Silicon nanoporous pillar arrays(Si-NPA)were used as functional substrates,and GaN/Si-NPA heterojunctions were prepared by chemical vapor deposition method.It was found that under Ga-rich condition,point defects such as gallium vacancy and nitrogen intersititial were easily introduced during the growing process of GaN,and had effect on the luminescence and electrical characteristics of the GaN/Si-NPA heterojunction.After high-temperature annealing treatments in ammonia atmosphere,the photoluminescence spectra of GaN/Si-NPA changed obviously.Both the intensity and the half width of the yellow luminescence peaks originated from point defects decreased eminently,which indicated the obvious decreasing of both the types and the concentrations of point defects.The electrical property tests showed that the samples both as-prepared and annealed exhibited rectification effect.Nevertheless,the leakage current density of GaN/Si-NPA decreased after the annealing treatments,accompanied with the increment of the turn-on voltage,the forward current density,the reverse breakdown voltage and the rectification ratio.By annealing GaN/Si-NPA heterojunction in ammonia atmosphere,the type and concentration of point defects could be effectively controlled.

关 键 词：氮化镓 硅纳米孔柱阵列 退火处理 缺陷 

分 类 号：O469[理学—凝聚态物理]