Thermal conversion of n-type GaAs:Si to p type in excess arsenic vapor

Annealing in excess arsenic vapor at 650 °C introduces thermal conversion of n-type Si-doped GaAs samples (n = 1.3 × 1018 cm−3) into p type. The observations are made by current-voltage and electron-beam induced current measurements. The donor concentration on the n side near the junction decreases after annealing. We present a comparison between the photoluminescence spectra of samples annealed under different conditions and an analysis of depth profile of the photoluminescence spectra. Our results underline the important role of gallium vacancies and gallium vacancy-silicon donor complex in the thermal conversion.