Fabrication of ZnSnO3 single crystal films on sapphire substrates by pulsed laser deposition for solar-blind photodetectors

Abstract

ZnSnO3 single crystal films were prepared on c-plane sapphire substrates using pulsed laser deposition and post-annealing methods. For the as-grown sample at 700 °C, post-annealing at 700 °C resulted in a significant improvement in the crystalline quality of the single crystal films, while post-annealing at 800 °C led to decomposition of ZnSnO3. Compared with the amorphous and mixed crystal ZnSnO3-based photodetectors (PDs), the single crystal ZnSnO3-based PD has a better light-to-dark current ratio (1.32 × 106) and higher responsivity (8.71 A/W) at 5 V under 254-nm UV (1.1 mW/cm2) illumination. Such a good performance serves as resounding validation of the remarkable potential of ZnSnO3 epitaxial films in the context of solar-blind PDs.