Photoreflectance Study of GaAs/GaAsP Strained-Barrier Quantum Well Structures

GaAs/GaAs1-xPx strained-barrier quantum well structures grown by metalorganic vapor phase epitaxy (MOVPE) have been investigated using photoreflectance (PR) spectroscopy. On the basis of the square-potential model, we have determined the band offsets at the heterojunction and their dependence on the phosphorus composition. It was found that in the GaAs/GaAs1-xPx strained-barrier quantum well, the band offsets are almost linearly dependent on the phosphorus composition in the range of x≤0.23. In addition, it was derived that the conduction band offset ratio Qc=0.57±0.05. This result is consistent with our previous study concerning GaAs/GaAsP "strained-well" quantum well structures.