High valence-band offset of GaSbAs-InAlAs quantum wells grown by molecular beam epitaxy

Photoluminescence measurements were made at 2-300 K on GaSbAs-InAlAs single quantum wells lattice matched to InP grown by molecular beam epitaxy. The experimental exciton transition energy from the first electron subband to the first heavy hole subband was analyzed with calculated values obtained from the envelope function method. The quantum well exciton transition energy for well widths of 10-300 Å is fitted to a large valence-band offset (ΔE_v) of 0.93 ΔE_g. The exciton linewidth increases with decreasing well width. The two dominant exciton line broadening mechanisms were found to be monolayer fluctuations of the well width and the band filling of electron.