Effect of Triton X-100 surfactant on structural, morphological, and optical properties of ZnS thin films deposited by spin coating method

Nano-crystalline Zinc sulfide (ZnS) thin films were deposited on glass substrates by spin coating method using thiol-amine co-solvent through Triton X-100 (TX-100) surfactant. The structural, morphological, and optical properties of the deposited ZnS films for with and without TX-100 surfactant was investigated by X-ray diffraction, scanning electron microscopy, and optical transmission spectroscopy. The X-ray diffraction results showed that hexagonal phase with (008) plane. The highest peak intensity was found from the surfactant-mediated film which originated at 2θ value of ~29.30°. The crystalline size increased but the dislocation density and lattice parameters are decreased for with surfactant than without surfactant. The SEM results showed surfactant mediated film offered a smoother and uniform surface with fewer crack than without surfactant film. The optical transmittance was found 62–70% and 80–86% in the visible region without and with surfactant respectively. At the same time, the band gap energy was found 3.71 eV and 3.80 eV for without and with surfactant correspondingly. All the results showed that the high-quality ZnS film using TX-100 surfactant may be used as buffer layer for TFSCs.