Optical properties of amorphous GaAs1−xNx film sputtering with different N2 partial pressures

Abstract

We study the optical properties of amorphous GaAs1−xNx films grown by radio frequency magnetron sputtering method with different N2 partial pressures. The surface morphology, the optical absorption, the Raman spectra, and optical constants of the films with different N2 partial pressures are reported. The appearance of the Raman peak at 245cm−1 of “GaAslike” and a shoulder at about 750cm−1 related to GaN indicates the formation of GaN clusters in GaAs matrix. The roughness decreases and the optical band gap of amorphous GaAs1−xNx films moves to short wavelength with increasing N2 partial pressure. The refractive index and the extinction coefficient of the films decrease with increasing N2 partial pressure, and it has been found that the amorphous GaAs1−xNx films with nonzero N2 partial pressure are transparent in red and near infrared wavelength regions.