Abstract:
Cathodoluminescence (CL) spectroscopy shows that even relatively low-dose keY light-ion
bombardment (corresponding to the generation of ~ 5 X 1019 vacancies/crrr') of wurtzite GaN
results in a dramatic quenching of visible CL emission. Postimplantation annealing at temperatures
up to 1050 °C generally causes a partial recovery of measured CL intensities, However, CL depth
profiles indicate that, in most cases, such a recovery results from CL emission from virgin GaN,
beyond the implanted layer due to a reduction in the extent of light absorption within the implanted
layer. In this case, CL emission from the implanted layer remains completely quenched even after
such an annealing. These results show that an understanding of the effects of ion bombardment and
postimplantation annealing on luminescence generation and light absorption is required for a correct
interpretation of luminescence spectra of GaN optically doped by keY ion implantation.
