Synthesis and characterization of pure and doped ZnS thin films by colloidal solution route

Abstract

Zinc sulphide (ZnS) is a wide band gap and eco-friendly II-VI chalcogenide material used in sensors, solar cells, catalysts, UV detectors, bio-imaging, and more. In addition, Cu-doped ZnS films are considered as possible substitutes for transparent conducting oxides (TCOs), while Na-doped ZnS and K-doped ZnS films can serve as a substitute for p-type material for unipolar p-n junction device fabrication due to their cost-effectiveness. The present work displays the properties of pure and X-doped ZnS (where X= Cu, Na and K) thin films deposited by the colloidal solution route. The influence of zinc precursors and film thickness on the structural, morphological, optical, electrical, and thermoelectric properties of the films was investigated. The results showed that the zinc precursor significantly affects the film properties, with ZnCl2 yielding the best carrier mobility among all other films. Cu-doped ZnS films showed improved optical transparency and electrical conducting properties, and Na/K-doped ZnS thin films exhibited p-type semiconducting behaviour, which could be tuned by varying the film thickness. These results suggest potential applications for ZnS films in various electronic devices, Cu:ZnS films as transparent conducting material, and Na/K-doped ZnS thin films in unipolar device fabrication. newline newline