EFFECT OF LIGHT ON THE DX CENTERS IN SI-DOPED AND TE-DOPED GAALAS

Deep level transient spectroscopy (DLTS) and constant temperature capacitance transient measurements have been performed on the DX centers under light illumination in GaAlAs alloys doped with Si and Te. Assuming that the effect of light is to ionize the DX centers, experimental DLTS spectra have been simulated numerically. The stimulated spectra reproduces qualitatively the spectra in Te-doped samples only. In Si-doped samples, the stimulated spectra cannot reproduce the light-induced peak reported recently by Jia et al. [J. Appl. Phys. 66, 5632 (1989)]. Our results confirm that this peak may be associated with a light-induced metastable center related to Si in GaAlAs.