Growth of large-area two-dimensional non-layered β-In 2 S 3 continuous thin films and application for photodetector device

In this work, the large-area two-dimensional non-layered β-In2S3 continuous thin films were grown on mica substrate by physical vapor deposition (PVD) at temperature of 980 °C using In2S3 powders as precursor. The 2D β-In2S3 thin films were transferred from mica substrate to SiO2/Si substrate. The back-gate field effect transistors (FETs) based on the 2D β-In2S3 thin films were fabricated using a conventional photolithographic technique. The morphology, thickness, crystal structure and optical property of the 2D β-In2S3 thin films as well as photoresponse performance of devices were characterized at room temperature under ambient condition. The results show that the 2D β-In2S3 continuous thin films are assembled from the 2D β-In2S3 flakes by tiling on each other with broad-area plane-to-plane contacts. The thickness of the 2D β-In2S3 films is in the range from 23 to 236 nm. The as-fabricated photodetectors exhibit highly stable and reproducible photoresponse properties with responsivity of 11.2 A/W and external quantum efficiency of 2.6 × 103% under 532 nm incident light with power density of 159.2 mW/cm2. The rise time and decay time of device are 90 ms and 80 ms, respectively. The 2D β-In2S3 thin films have very good application prospects in the field of electronic and optoelectronic devices.