光栅光谱仪前置和后置分光构型下光调制反射谱应用的不同特征  

The different characteristics of dark and bright configurations of photoreflectance based on grating spectrometer

作　　者：詹嘉 查访星[1] 顾溢 ZHAN Jia;ZHA Fang-Xing;GU Yi(Department of Physics,Shanghai University,Shanghai 200444,China;Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China)

机构地区：[1]上海大学理学院物理系,上海200444 [2]中国科学院上海技术物理研究所,上海200083

出　　处：《红外与毫米波学报》2024年第5期615-620,共6页Journal of Infrared and Millimeter Waves

基　　金：国家自然科学基金面上项目(61874069)。

摘　　要：光调制反射光谱因其高灵敏的特性而广泛的用于研究半导体及其表面与界面特性。基于光栅光谱仪其测量光路根据分光顺序的不同可以分为前置分光构型(暗构型)与后置分光构型(亮构型)。本文以InP/In_(0.52)Ga_(0.48)As/InP异质结外延结构为例,阐述了两种光路构型的不同特点和适用条件。揭示前分光构型能很好地分离荧光谱线与调制谱线;后分光构型则有利于采用较强调制激光而有效提取荧光较弱的电子结构信息。后分光构型实验中还观察到,当使用低能量激光(1064 nm)只调制激发窄带隙的InGaAs层时,却观察到宽带隙InP的谱线形的反常现象。这起源于光生载流子的界面电场调制作用,表明界面激发的后分光构型可作为一种非接触“电调制”方法而方便地应用于宽带半导体的异质外延结构的研究。Photoreflectance(PR)has been widely used for the characterization of various semiconductors as well as their surface and interface properties due to its non-destructive and high sensitivity virtues.From the viewpoint of the employment of monochromator,the experimental setup may be classified into dark and bright configurations,which were applied to characterize the heterostructure of InP/In_(0.52)Ga_(0.48)As/InP grown by molecular beam epitaxy.It reveals that the front configuration well separates the luminescence from the modulation signal while the backside configuration benefits the extraction of weak modulation signals with the employment of high excitation power.Based on the backside configuration,we also observed a below band-gap excitation phenomenon,i.e.that the modulation signal of InP exhib-its under the excitation of energetically low modulation light(1064 nm laser).The result demonstrates that the backside configuration may be employed as a contactless electro-modulation technique for the characterization of wide band gap semiconductor heterostructures.

关 键 词：光调制反射光谱 半导体异质结 INGAAS/INP 内建电场 

分 类 号：O472.3[理学—半导体物理]