Study on the Band Line-up of GaAsSb/GaAs Quantum Wells

Because of the band-bending effect, the blue-shift on the emission wavelength of GaAsSb/GaAs QW laser was observed as the cavity length was shortened. We utilized this effect to investigate the band line-up of the GaAsSb/GaAs QW. Through a simulation based on solving the Poisson and Schrödinger equations simultaneously for the band structure and optical gain of GaAsSb/GaAs QW, we found that the valence band offset ratio (Q) of the unstrained GaAs0.64Sb0.36/GaAs is 1.02, and the unstrained band-gap bowing parameter of GaAsSb is 1.31. In the calculation, band filling effect and the band-gap shrinkage induced by many-body effect were considered.