Abstract

A new optical spectroscopy method is applied to MBE-grown GaAs/Al_xGa_1−xAs multiquantum-well (MOW) structures to derive microstructural details of the layers. Fine structures are observed in the heavy-hole as well as in the light-hole excitonic region of MOW samples at low temperatures. Particularly interesting is the light-hole exciton line shape change (similar to line-narrowing effects), which was observed while the photoluminescence detection-filter-frequency was varied. From the analysis of the exciton line shape change, in terms of the peak position and the halfwidth, some information on microscopic structural variations of MQW is derived. Applications of our methods in higher-quantized energy levels as well as in other superlattice systems are discussed.

© 1985 Optical Society of America