Thephyphen;GaAs/Phyphen;Ga1minus;xAlxAs isotype heterojunction, that occurs in doubleheterostructure laser material, is studied experimentally and theoretically. In good quality liquid phase epitaxially grown material, carrierhyphen;concentration profiles show the presence of hole accumulation in the small bandhyphen;gap material and hole depletion in the large bandhyphen;gap material. When either the layer thickness varies across the diode or the heteroboundaries are not abrupt, the profile across the isotype heterojunction becomes smeared. Hence, this profiling method can provide a sensitive measure of material quality. Furthermore, the analysis accounts for the possible presence of interface states, which can affect band bending at heteroboundaries. It is shown that this band bending can affect the recombination of carriers, and therefore their lifetimes and efficiency.
展开▼
