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Radiation-produced defects in doped and nominally undoped n-GaN with charge carrier concentrations in a range of 4 × 10 16 cm -3 to about 2 × 10 18 cm -3 are investigated. Layers of n-GaN are irradiated with fast electrons at 0.9 MeV, 60 Co gamma rays and protons at 150 keV. The production rates of radiation defects in n-GaN are estimated and compared with literature data. Annealing processes of radiation defects in n-GaN in the temperature range 100-700 °C are also discussed. The annealing behavior appears to be complicated. Two temperature intervals, from T= 100 to 400°C and from T = 500 to 700°C, are characteristic for modification and annealing processes of radiation-produced defects in n-GaN.

The electrical properties of the n-GaN and n-InN, subjected to proton irradiation, are studied. The irradiation of the n-InN results in an increasing concentration of charge carriers, whereas strong compensation effects take place in the proton-irradiated n-GaN. The annealing behavior of the radiation-induced defects in both materials is discussed briefly.

Formation and annealing of radiation-induced defects in doped and nominally undoped n-GaN are investigated by means of electrical measurements and Raman spectroscopy. The production rate of defects turned out to be dependent on the dopant concentration. This suggests that at least one kind of native defects is involved in impurity–defect interactions at room temperature. Two prominent stages of defect annealing are revealed. The annealing processes at T ≥100°C are associated with mobile native defects. A considerable fraction of radiation defects is still present in the materials after annealing to T ≥750°C.