Preparation and characterization of zinc sulfide thin film by electrostatic spray deposition of nano-colloid

Abstract

In this investigation, condensed and adhesive zinc sulfide (ZnS) layers were productively sprayed onto Fluorine doped Tin Oxide glass substrate at room temperatures using a facile, non-vacuum and economical electrostatic spray deposition (ESD) method. Used ZnS colloidal in the ESD process prepared by a one-pot thermolysis synthesis method. The effects of applied voltage, liquid flow rate, and distance of the nozzle to substrate on the morphology of ZnS thin films, were investigated. It revealed optimized conditions at the voltage of 24 kV, the flow rate of 1 μl/min, and nozzle to substrate distance of 8 cm. The ultraviolet-visible absorption spectroscopy revealed direct optical band gap of the deposited layer is around 3.44 eV. At a wavelength larger than 350 nm, the visible region (transparency area) of ZnS film was observed. Energy dispersion X-ray analysis and scanning electron microscope showed the ZnS film has a thickness of more than 300 nm with Zn1-xS (x ≈ 0.3–0.4) chemical composition.