Growth and optical properties of amorphous Be0.13Zn0.38O0.49 thin films prepared by radio frequency magnetron sputtering

Radio frequency reactive magnetron sputtering was used to grow thin films of BeZnO on Si(1 0 0) substrates at temperature <52 °C. X-ray diffraction patterns of the films revealed no structure, suggesting the films have an amorphous nature. By using X-ray photo-electron spectroscopy and Rutherford proton elastic backscattering spectroscopy the concentration of Be and Zn atoms were determined to be 13 mol% and 38 mol%, respectively. The thicknesses and optical constants of the films were derived in the wavelength range 290–1600 nm, using the Cauchy–Urbach model. Refractive indices and extinction coefficients of the amorphous Be0.13Zn0.38O0.49 films were determined to be in the range n = 1.75–2.19 and κ = 2.2 × 10−7–0.27, respectively. Analysis of the absorption coefficient shows the optical ‘bandgap’ energy of the films to be 4.03 ± 0.04 eV.