摘要
在比较宽的组份范围内首次报道了MBE GaAs_(1-x)Sb_x混晶的喇曼光谱。发现声子频移强烈地依赖于Sb的组份x,而光学声子的双模行为仅仅在x>0.15时才发现,用远红外傅里叶光谱已证实这一结果。类GaAs LO模的线形分析表明本文的GaAs_(1-x)Sb_x质量较好。用质量缺陷模型和渗流理论讨论实验结果,用团聚效应解释x>0.15时声子的双模行为并估算了平均团聚尺寸。理论与实验结果符合得很好。
The Raman spectra of MBE-grown GaAs_(1-x)Sb_x in a relatively wide range of composition are reported for the first time. It is observed that the frequency shift of phonons strongly depends on the composition x of Sb. The two-mode behavior of optical phonons is observed only when the composition x of Sb is larger than 0.15. This result is confirmed by the reflectance spectra measured by using a Fourier transform spectrometer. The analysis of GaAs-like LO lineshape shows that the MBE-grown GaAs_(1-x)Sb_x material used in this work has good quality. The experimen tal results are discussed by using the mass defect model and percolation theory.
出处
《红外与毫米波学报》
SCIE
EI
CAS
CSCD
北大核心
1991年第5期321-325,共5页
Journal of Infrared and Millimeter Waves
