Free carrier lifetime reduction in shock-compressed GaAs

Understanding the changes in dynamic carrier properties, including lifetime, are important for operation of gallium arsenide (GaAs) based optoelectronic devices. Significant carrier lifetime reductions were determined in GaAs:Te, shock-compressed along [100] to 4 GPa, using time- and spectrally-resolved photoluminescence (PL) measurements. Lifetime changes were extracted from PL signals extending over five orders of magnitude following a short excitation pulse in single event shock experiments. Several time-resolved recombination mechanisms showed a linear lifetime reduction in marked contrast to earlier hydrostatic pressure results. The present results suggest that the lifetime reaches a minimum at the direct-to-indirect band gap transition.