Abstract
We have investigated the photoreflectance characteristics for In\ulcornerGaAs/GaAs heterojunction structure grown by molecular beam epitaxy (MBE). The E\ulcorner bandgap energy of In\ulcornerGa\ulcornerAs at room temperature was observed at about 1.3 eV. From this result, the indium composition x value was calculated. The shoulder peaks were observed higher than E\ulcorner peaks, and peak positions were shifted toward 12 meV to 70 meV higher energy with increasing doping concentrations. The shoulder peaks can be observed by In segregation and re-evaporation. However, we think that indium re-evaporation cause th shift of shoulder peaks after epilayer growth.