The properties of spray-deposited zinc sulfide thin films using trisodium citrate complexant

Zinc sulfide thin films were deposited on soda-lime glass substrates by chemical spray pyrolysis technique using trisodium citrate complexant. The films were deposited at substrate temperatures of 300 to 400 °C using 0.1 M zinc chloride, 0.1 M thiourea, and 0.01 M trisodium citrate. The thin films’ transmittance is between 40.83 and 50.86% at 550 nm, and energy band gap varied between 3.52 and 3.72 eV. The films have very high refractive indices in the range of 3.07 to 4.02 at 550 nm. The X-ray diffraction (XRD) analyses of the films revealed hexagonal structure. The crystallite size changed between 7.030 and 45.486 nm. The surface morphology is flower-like, dense, and contains rectangular nanorod-like particles and cracks. Raman spectroscopy revealed the presence of first-order (transverse optic (TO) and longitudinal acoustic), second-order (2TO and 2LO), and third-order (3LO) Raman phonons. The Fourier transform infrared spectra indicate the presence of chemical bonds in the thin films, while photoluminescence indicates near band edge emissions. The contact angle revealed hydrophilic nature of the deposited ZnS thin films.