异质外延GaN中穿透位错对材料发光效率的影响  

Influence of Threading Dislocations on the Luminescence Efficiency of GaN Heteroepitaxial Layers

作　　者：高志远[1] 郝跃[1] 李培咸[1] 张进城[1] 

机构地区：[1]西安电子科技大学微电子学院宽禁带半导体材料与器件教育部重点实验室,西安710071

出　　处：《Journal of Semiconductors》2008年第3期521-525,共5页半导体学报（英文版）

基　　金：国家重点基础研究发展规划资助项目(批准号:2002CB3119;513270407)~~

摘　　要：用阴极射线致发光(CL)法、透射电子显微镜(TEM)和X射线衍射(XRD)法研究了异质外延GaN材料的发光性质与结构特性的关系.结果表明,GaN外延层中的穿透位错是材料有效的非辐射复合中心,但GaN的CL带边峰强度并不随位错密度的增加而减少.两步法生长GaN形成的马赛克结构的亚晶粒尺寸和晶粒间合并产生的位错的弯曲程度是影响材料发光效率的关键.We study the relationship between microstructure and luminescence efficiency for GaN heteroepitaxial films by cathodoluminescence （CL） ,transmission electron microscopy,and X-ray diffraction. Even though threading dislocations in GaN epitaxial layers have been demonstrated to be effective nonradiative recombination centers,the CL band edge peak intensity does not decrease as the dislocation density increases. The luminescence efficiency of GaN is found to be affected both by the grain size of the mosaic structural GaN formed by two-step growth and by the bend extent of dislocations formed during the coalescence of sub-grains.

关 键 词：GAN 穿透位错 非辐射复合 发光效率 

分 类 号：TN304[电子电信—物理电子学]