Cathodoluminescence study of ion implanted GaN

The effect of ion-beam-produced defects as well as H, C, and O, introduced by ion implantation, on the luminescence from wurtzite GaN is studied by cathodoluminescence (CL) spectroscopy. Results indicate that even relatively low dose keV light-ion bombardment results in a dramatic quenching of 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 defect-related light absorption within the implanted layer. Results also show that H, C, and O, presumably in combination with point defects, give rise to yellow luminescence in GaN, while lattice defects alone (as well as the other species implanted such as B, N, and Si) do not give rise to yellow luminescence.