Article

Effect of native defects on optical properties of InxGa1-xN alloys

Materials Sciences Division, Lawrence Berkeley National Laboratory and Department of Materials Science and Engineering, University of California, Berkeley, California 94720
Applied Physics Letters (Impact Factor: 3.52). 11/2005; DOI: 10.1063/1.2108118
Source: IEEE Xplore

ABSTRACT The energy position of the optical-absorption edge and the free-carrier populations in In x Ga 1-x N ternary alloys can be controlled using high-energy 4 He + irradiation. The blueshift of the absorption edge after irradiation in In-rich material (x≫0.34) is attributed to the band-filling effect (Burstein-Moss shift) due to the native donors introduced by the irradiation. In Ga-rich material, optical-absorption measurements show that the irradiation-introduced native defects are inside the band gap, where they are incorporated as acceptors. The observed irradiation-produced changes in the optical-absorption edge and the carrier populations in In x Ga 1-x N are in excellent agreement with the predictions of the amphoteric defect model.

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