Carrier lifetime under low and high electric field conditions in semi-insulating GaAs

The mobility lifetime product of holes and electrons under low electric field conditions was determined by alpha spectroscopy using SI-GaAs as a photo conductivity detector. The lifetime in high electric field (≥ 104V/cm) of electrons was investigated with Schottky diodes. Both results were analyzed as a function of substrate resistivity and trap concentrations. We identified the ionized arsenic antisite defect (EL2+) as the dominant electron trap in the high field region and determined the capture cross-section as being (8.0 ± 0.6) × 10−14 cm2.