DEGRADATION OF PHOTOLUMINESCENCE FROM QUANTUM-WELLS GROWN ON TOP OF LOW-TEMPERATURE BUFFERS

The high-resistivity properties of low-temperature (200-300-degrees-C) molecular-beam-epitaxy-grown GaAs and AlGaAs have great potential for device applications. The purpose of this study is to examine the effect of low-temperature buffers (LTB) on the crystal quality of epilayers grown on top. Photoluminescence (PL) from quantum wells grown at regular growth temperatures (620-degrees-C) is found to be sensitive to changes in crystal quality introduced by the LTB. Limiting LT AlGaAs buffer thicknesses to a critical thickness is found necessary for growing layers with good quantum-well PL.