Photoluminescence of carbon-implanted GaAs

Abstract

The 5-K photoluminescence (PL) spectra of undoped semi-insulating GaAs are observed as a function of carbon implantation dose (after 850°C annealing using a SiO2 cap). Results show that although the intensity of the bound exciton line at 1.514 eV remains fairly independent of carbon concentration up to 1017 cm−3 carbon, the intensity of the conduction band to acceptor peak at ∼1.494 eV increases monotonically with carbon implant dose. This is the first direct confirmation that the 1.494-eV transition is due to carbon. The observed correlation between implanted carbon doses and PL intensities at high excitation levels is the basis of an analytic technique for C assessment in GaAs.