Electrical and Optical Properties of 1 MeV-electron irradiated AlxGa1-xN

Abstract

ABSTRACTThe optical and electrical properties of Si doped GaN and Al0.20Ga0.80N films irradiated with 1 MeV electrons at a fluence of 1×1017 cm−2 are investigated using cathodoluminescence (CL), variable-temperature Hall-effect, and deep level transient spectroscopy (DLTS) measurements. The CL spectra measured at 6 K show peak luminescence intensity of the near band edge decreases, on average, by 50% after electron irradiation, indicating the creation of non-radiative recombination centers which are stable at room temperature. At room temperature, the free carrier concentration decreases significantly in both the GaN and AlGaN samples following the irradiation, and the carrier removal rate depends strongly on the initial carrier concentration. DLTS measurements show three electron traps in the as-grown Al0.20Ga0.80N. Following 1 MeV electron irradiation of the Al0.20Ga0.80N sample, three additional electron traps labeled R2, R3, and R4 are observed. The first two traps appear to correspond to radiation-induced traps reported in GaN while the latter appears to be unique to AlGaN.