Zinc oxysulfide (ZnOS) nano-thin film has been deposited on a p-type silicon and glass substrate via the hydrothermal deposition method at a temperature of 200ºC. The crystallographic information and morphological analysis of zinc oxysulfide (ZnOS) thin film have been obtained using X-ray diffraction (XRD) patterns and field effect scanning electron microscopy (FESEM). The ZnOS thin film chemical composition was examined using energy-dispersive X-ray spectroscopy (EDX). Ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy have been utilized for optical analysis. The electrical and electro-optical measurements of ZnOS thin film have been carried out by I-V characteristics in the visible light environment with a power density of 30 mW/cm2. Zinc oxysulfide (ZnOS) thin film was found to be an excellent example of simple responsive photodetection in visible light. The ZnOS thin film has a response time of 1.46 s and a recovery time is equal to 1.32 s. The specific detectivity of the deposited thin film was found to be 3.81×108 Jones. The responsivity of the deposited thin film is found 7.08×102 mA/W. 
Keywords: Zinc oxysulfide, hydrothermal method, heterojunction, photosensor.