Influence of interface bonds and buffer materials on optical properties of InAs/AlSb quantum wells grown on GaAs substrates

Optical properties of InAs/AlSb multiquantum wells (MQWs) epitaxially grown on GaAs substrates with a buffer laver 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 AI-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. (C) 2000 Published by Elsevier Science B.V. PACS: 81.10; 61.43; 78.60; 78.66; 61.10.N.