Anomalous intensity degradation in the temperature-dependent photoluminescence of 50Å GaAs/AlGaAs multiple quantum wells grown on on-axis and off-axis substrates
Abstract
Temperature-dependent photoluminescence (PL) spectroscopy from 10 K up to 300 K was performed on 50 Å GaAs/AlGaAs multiple quantum wells (MQW's) grown on on-axis and off-axis GaAs substrates. An anomalous dip in the integrated PL intensity in the 80 K to 130 K region was observed for the on-axis sample. The structural similarity of the two samples was verified via X-Ray diffractometry (XRD). Thus, differences in the PL data is attributed to deep-level impurities introduced during the MBE growth process. This assertion is verified by deep level transient spectroscopy (DLTS).