Temperature-dependent photoresponse of monolayer MoS₂ film grown by pulsed laser deposition

We report the preparation and photoresponse of MoS₂ films with different layers grown on c-Al₂O₃ by pulsed laser deposition (PLD). The phonon modes and crystallographic orientation discussed by Raman scattering and X-ray diffraction (XRD) prove that the MoS₂ films are of pure 2H-phase. The S/Mo ratio of film is identified as 1.92:1 derived by X-ray photoelectron (XPS) experiments. The blue and red shifts of the Mo 3d peaks for XPS data indicate the existence of oxidation and sulfur defects in the films. Moreover, by Raman and photoluminescence (PL) mapping, the film thickness is proven to be uniform. The temperature-dependent photoresponse of monolayer MoS₂ film indicates that the temperature plays an important role in the photoresponse intensity and response time. The present results can provide a reference for further improving the performance of MoS₂-based photodetectors.