Photocapacitance study of pressure-induced deep donors in GaAs: Si

Photocapacitance transient measurements in GaAs: Si under pressures of 33 and 38 kbar are reported for the first time. The optical ionization energy of pressure-induced deep donors in GaAs was determined to be 1.44±0.04 eV. The low-temperature capture times of photoexcited carriers were also measured and the results indicate that persistent photoconductivity would occur in GaAs under pressures in excess of 30 kbar. These results show that qualitatively the pressureinduced deep donors in GaAs are very similar to the $\mathrm{DX}$ centers in ${\mathrm{Ga}}_{1-x}{\mathrm{Al}}_x\mathrm{As}$ alloys in terms of their optical properties.