Optical and Electrical Properties of GaN:Mg Grown by MOCVD  

MOCVD生长的GaN:Mg外延膜的光电性质(英文)

作　　者：王莉莉[1] 张书明[1] 杨辉[1] 梁骏吾[1] 

机构地区：[1]中国科学院半导体研究所,北京100083

出　　处：《Journal of Semiconductors》2008年第1期29-32,共4页半导体学报（英文版）

基　　金：国家自然科学基金资助项目(批准号:60506001,60576003,60476021)~~

摘　　要：Mg-doped GaN layers prepared by metalorganic chemical vapor deposition were annealed at temperatures between 550 and 950℃. Room temperature （RT） Hall and photoluminescence （PL） spectroscopy measurements were performed on the as-grown and annealed samples. After annealing at 850℃, a high hole concentration of 8 × 10^17 cm^-3 and a resistivity of 0. 8lΩ·cm are obtained. Two dominant defect-related PL emission bands in GaN.. Mg are investigated; the blue band is centered at 2. 8eV （BL） and the ultraviolet emission band is around 3.27eV （UVL）. The relative intensity of BL to UVL increases after annealing at 550℃, but decreases when the annealing temperature is raised from 650 to 850℃, and finally increases sharply when the annealing temperature is raised to 950~C. The hole concentration increases with increased Mg doping, and decreases for higher Mg doping concentrations. These results indicate that the difficulties in achieving high hole concentration of 10^18cm^-3 appear to be related not only to hydrogen passivation, but also to self-compensation.用MOCVD技术生长GaN:Mg外延膜,在550～950℃温度范围内,对样品进行热退火,并进行室温Hall、光致发光谱(PL)测试.Hall测试结果表明,850℃退火后空穴浓度达到8×1017cm-3以上,电阻率降到0.8Ω.cm以下.室温PL谱有两个缺陷相关发光峰,位于2.8eV的蓝光峰(BL)以及3.27eV附近的紫外峰(UVL).蓝光峰对紫外峰的相对强度(BL/UVL)在550℃退火后升高,之后随着退火温度的升高(650～850℃)而下降,继续提高退火温度至950℃,BL/UVL急剧上升.空穴浓度先随着Mg掺杂浓度的增加而升高;但继续增加Mg掺杂浓度,空穴浓度反而下降.这些结果表明要实现空穴浓度达1018cm-3,不仅要考虑H的钝化作用,还要考虑Mg受主的自补偿效应.

关 键 词：Hall effect PHOTOLUMINESCENCE P-GAN 

分 类 号：TN304.055[电子电信—物理电子学]