Thermal escape process of photogenerated carriers from GaAs single-quantum-well contained in GaAs/AlAs superlattices

Thermal escape process of carriers has been investigated by steady-state and time-resolved photoluminescence (PL) spectroscopy in GaAs single-quantum-well (SQW) contained in GaAs/AlAs short-period superlattices (SPSs) over a wide temperature (T) range between 15 and 300 K. A typical PL spectrum indicates two emission bands corresponding to SQW and SPS layers. When the sample temperature is increased from 15 K, the PL intensity of SQW increases and reaches the maximum value at 50 K, while the PL intensity of SPS drastically decreases below 60 K. With further increase in temperature up to 120 K, the PL intensity of SPS increases. These results indicate the following processes: in the region of 15