Optical band gap of zinc nitride films prepared by reactive rf magnetron sputtering

摘要

Polycrystalline Zn3N2 films are prepared on Si and quartz glass substrates by RF magnetron sputtering at room temperature. The structural and optical proper-ties are studied by X-ray diffraction and double beam spectrophotometer, respectively. X-ray diffraction indicates that the Zn3N2 films deposited on Si and quartz glass substrates both have a preferred orientation in (321) and (442), also are cubic in structure with the lattice constant a=0.9847 and 0.9783 nm, respectively. The absorption coefficients as well as the film thickness are calculated from the transmission spectra, and their dependence on photon energy is examined to determine the optical band gap. Zn3N2 is determined to be an indirect-gap semiconductor with the band gap of 2.11(2) eV. (C) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.