Bismuth Effects on Electronic Levels in GaSb(Bi)/AlGaSb Quantum Wells Probed by Infrared Photoreflectance
CHEN Xi-Ren1, SONG Yu-Xin2, ZHU Liang-Qing1, QI Zhen1, ZHU Liang1, ZHA Fang-Xing3, GUO Shao-Ling1, WANG Shu-Min2,4, SHAO Jun1**
1National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 2State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 3Department of Physics, Shanghai University, Shanghai 200444 4Photonic Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, G?teborg S-412 96, Sweden
Abstract：GaSb(Bi)/Al0.2Ga0.8Sb single quantum wells are characterized by a Fourier transform infrared spectrometer-based photoreflectance method at 77 K. Spatially direct and indirect transitions between the electronic levels at and above the effective band gap are well resolved. The shifts of the electronic levels with Bi incorporation are identified quantitatively. The results show that the upshift of the valence band edge is clarified to be dominant, while the Bi-induced downshift of the conduction band edge does exist and contributes to the band gap reduction in the GaSbBi quantum-well layer by (29±6)%.
2015, Vol. 32 
