Point defects in gamma-irradiated n-GaN

Radiation-induced point defects and their annealing in silicon-doped n-GaN have been investigated by means of Hall effect measurements and Raman spect roscopy. Correlated compensation effects due to simultaneous introduction o f donor and acceptor centres are observed in irradiated n-GaN. The defect p roduction rate is dependent on the dopant concentration. This means that th e model of all native defects immobile at room temperature is not true. The behaviour of radiation-induced defects upon heating is complicated, exhibi ting two prominent stages of reverse annealing. The presence of radiation d efects is still observable after annealing to T = 750 degrees C.