Wavelength tunable photoluminescence of ZnO1-xSx alloy thin films grown by reactive sputtering

ZnO1−xSx alloy thin films with various S contents were deposited on glass substrates by reactive sputtering. The films were grown in high crystalline quality and strong preferential crystallographic orientation. Variations of the lattice constant c followed Vegard's law. X-ray photoelectron spectroscopy confirmed the substitution of O by S in ZnO. The composition dependence of the band gap energy in ZnO1−xSx system was investigated and the band gap bowing parameter was estimated to be about 1.46 eV. The incorporation of S led to the expected redshift of the band gap related photoluminescence emission of ZnO1−xSx films up to 320 meV. The results indicate that ZnO1−xSx films could hold the prospect for the development of ZnO based quantum structures.