Influence of interface bonds and buffer materials on optical properties of InAsrAlSb quantum wells grown on GaAs substrates

Optical properties of InAsrAlSb multiquantum wells MQWs.epitaxially grown on GaAs substrates with a buffer layer are shown to be dependent on the type of the interface bond and the buffer layer material. Combinations of the two possible interface bond configurations In–Sb and Al–As.with the two buffer layer materials InAs and AlSb. were prepared by molecular beam epitaxy. The photoluminescence intensity PL. of MQWs was considerably higher for two kinds of structures: 1. the In–Sb bond with the AlSb buffer or 2. the Al–As bond with the InAs buffer. The two other possible combinations resulted in a drastically reduced PL intensity. X-ray diffraction XRD.measurements revealed that lattice matching between the average lattice constant of MQW and the buffer layer plays a key role in determining the PL intensity. q2000 Published by Elsevier Science B.V.