分子束外延n-GaAs/SI-GaAs薄膜材料的拉曼光谱研究  

Raman Spectra Studies of MBE-Grown n-GaAs/SI-GaAs Films

作　　者：王斌[1] 徐晓轩[1] 秦哲[1] 宋宁[1] 张存洲[1] 

机构地区：[1]南开大学泰达应用物理学院

出　　处：《光谱学与光谱分析》2008年第9期2103-2106,共4页Spectroscopy and Spectral Analysis

基　　金：教育部“振兴计划”项目基金(A01504)资助

摘　　要：用分子束外延(MBE)技术,在GaAs(100)衬底上生长了不同Si掺杂浓度(从1016cm-3到1018cm-3)的n-GaAs薄膜。通过在室温下拉曼光谱的测量对n-GaAs薄膜的谱形进行了分析,拉曼位移出现了明显的移动,光学横模TO峰相对的增强,光学纵模LO峰相对的减弱。文章分析了原因这是由于Si掺杂浓度不断的提高,致使界面失配位错不断地提高造成的,内部应力也在不断的增大,原来的晶格振动平衡被破坏,四价Si替代了三价Ga致使谱线移动。并且由于横声子模具有Raman活性,横声子模被相对的增强了。实验结果与理论是互相吻合的。n-GaAs films doped with Si were grown by MBE on semi-insulated GaAs （100） substrates. The films with different doping concents were characterized by Raman spectra at room temperature. It is obviously that the Raman peaks shifted. Some peaks were enhanced and some were weakened. This is attributed to the fact that the higher the doping contents, the highertge lattice mismatch. And the lattice misfit induced the imperfection in epitaxy layers. This experimental result coincides with the theory.

关 键 词：分子束外延 n-GaAs/SI-GaAs 掺杂浓度 拉曼光谱 

分 类 号：O433.1[机械工程—光学工程]