Photocapacitance measurements were used to study liquid-phase epitaxially grown n-type Ga0.7Al0.3As crystals at various temperatures. The measurements revealed deep levels which were located at 0.5eV below the conduction band, and 1.5eV above the valence band. The thermal activation energy for electron capture at the ionized Ec - 0.5eV level was found to be 0.031eV. Optical hole emission from the Ev + 1.5eV level was enhanced with increasing sample temperature. After 1.5eV monochromatic light pre-irradiation, the Ec - 0.5eV level was detected in intentionallly undoped samples.

Photocapacitive Detection of Hole Emission from DX Centers in n-Type GaAlAs Doped with Te A.Murai, Y.Oyama, J.Nishizawa: Journal of Applied Physics, 2000, 87[1], 223-7