Growth of non-polar a-plane ZnO1−xSx films by pulsed laser deposition

A series of non-polar ZnO1−xSx thin films with different S contents were grown on r-plane sapphire substrates by pulsed laser deposition. The S content in the ZnO1−xSx thin films was adjusted by changing the growth temperature. Up to 20 at% S was introduced into ZnO film without changing the single-phase hexagonal structure. Based on the X-ray diffraction analysis, the ZnO1−xSx thin films with S content below 19 at% exhibit unique non-polar 〈112−0〉 orientation, while the films with S content above 19 at% show 〈0 0 0 1〉 and 〈112−0〉 mixed orientations. X-ray photoelectron spectroscopy confirmed the chemical states of Zn, O and S elements in the ZnO1−xSx films.