PHOTOREFLECTANCE STUDY OF INXGA1-XAS GAAS SINGLE QUANTUM-WELLS

In order to gain information about the band offset in the strained layer InxGa1-xAs/GaAs system we have investigated photoreflectance (PR) from two single quantum well (SQW) samples at 300 and 77 K. Our samples had well widths Lz=110 A ̊ (sample 1) and Lz=107 A ̊ (sample 2) with x=0.11 (sample 1) and x=0.19 (sample 2). By studying the polarization dependence of the PR at 300 K using an internal reflection mode we have identified spectral features corresponding to conduction to light- and heavy-hole transitions. Good agreement between our experimental results and an envelope function calculation (including strain) is obtained for conduction band offset Qc=0.45 ±0.07 (sample 1) and Qc=0.67±0.07 (sample 2). These values comply with the compositional dependence of Qc proposed by M.J. Joyce et al. [Phys. Rev. B 38 (1988) 10978]. © 1990.