OPTICAL-PROPERTIES OF ALPHA-IRRADIATED AND ANNEALED SI-DOPED GAAS

The influence of irradiation by cu particles and subsequent isochronal annealing on n-GaAs doped with silicon, was investigated. Photolumine scence (PL) studies revealed the formation of an induced radiation cen ter at 1.486 eV. In addition to the PL investigation we also employed capacitance-voltage (C-V) measurements and deep level transient spectr oscopy (DLTS). The C-V measurements indicate a slight reduction in n-t ype carriers in treated samples and the DLTS spectra showed a number o f commonly observed deep levels in irradiated samples (not annealed), which disappear after annealing. Based on the experimental evidence we propose that the 1.486 eV band is due to a donor-acceptor-pair transi tion. Alternative mechanisms are also discussed. (C) 1997 American Ins titute of Physics.