Capture cross section of electron-irradiation-induced defects in bulk GaN grown by halide vapor phase epitaxy
2014 (English)Manuscript (preprint) (Other academic)
Electron-irradiation-induced defects in GaN grown by halide vapor phase epitaxy is studied by deep level transient spectroscopy in which the capture cross section and its temperature dependence of the deep levels was determined by the filling pulse method. Before irradiation, one trap level, labelled ET4 (EC – 0.244 eV), was observed. After performing electron irradiation with an energy of 2 MeV at a fluence of 5 × 1016 cm-2, four deep trap levels, labelled ET1 (EC – 0.178 eV), ET2 (EC – 0.181 eV), ET3 (EC – 0.256 eV) and ET5 appeared. After annealing at 650K for 2 hours, only two irradiation induced deep levels, ET1 and ET3, were observed. By varying the rate windows, the temperature dependence of the capture cross section of the two deep levels ET1 and ET2 and ET3 was studied. The temperature behavior of ET2 and ET3 capture cross section is independent on temperature whereas the capture cross section of the deep level ET1 depends strongly on the temperature. It is suggested that electron capturing is govern by a multiphonon process to the level ET1.
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IdentifiersURN: urn:nbn:se:liu:diva-112261OAI: oai:DiVA.org:liu-112261DiVA: diva2:764665