MOCVD生长GaN膜的光调制反射谱研究

Photoreflectance Study of GaN Films Grown by MOCVD

采用光调制反射光谱（PR）研究了（0001）晶向蓝宝石村底上MOCVD方法生长的单晶六角GaN薄膜的室温光学性质。测得六角GaN薄膜的禁带宽度为3．400eV，对PR谱的调制机理进行了分析，发现信号来自缺陷作用下的表面电场调制。光吸收增和光反射谱的测量，得到3．39eV的光学吸收边和3．3eV的反射峰，证实了光调制反射光谱的结果。

Photoreflectance (PR ) was used to study the optical properties of . single crystal hexagonal GaN films on (0001) sapphire substrate grown by metalorgainic chemical vapor deposition (MOCVD) in this paper. The energy gap of hexagonal GaN was determined as 3. 400 eV, and the possible origin of the PR signal was studied and attributed to the modulation of the surface field and lineshape broadening of defects. Optical absorption and reflection were measured. The optical absorption edge of 3. 39 eV, and the reflectivity peak at 3. 3 eV confirmed the results of photoreflectance.