Synthesis and Characterization of ZnS:Cu Thin Films as Gas Sensor Application

For use in gas sensor packages, zinc sulfide (ZnS) thin films have been created utilizing the sol-gel dipping deposition process with copper (Cu) doping. Nitrogen dioxide (NO2) and hydrogen sulfate (H2S) are the measurement's goal gases. The probability of Cu doping was 1, 3 and 5 wt%. For morphological, structural, and microstructural characterization, Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), and UV-visible measurements were used to determine optical properties. The presence of a hexagonal phase was shown by XRD patterns. Due to the more microstrain that brought about copper incorporation, with growing copper inclusion in ZnS thin films, there was a constant decline in particle length. The size variety of the produced hexagonal ZnS crystals turned into 9-17 nm, with a median length of approximately 12 nm. The band hole of the films fell from 3.2 eV for ZnS to 2.8 eV for 5% Cu-doped ZnS film, which could be because copper inclusion ended in an extra organized hexagonal shape. According to the outcomes of sensing homes, ZnS: 3%Cu film for NO2 gas at 150 °C and ZnS: 5%Cu for H2S gas at 250 °C had the best sensitivity.