Influence of deposition techniques on quality and photodetection properties of tin disulfide (SnS2) thin films

Abstract

Tin disulfide (SnS2) is one of the potential candidates for optoelectronics because of its chemical and environmental stability accompanied by favourable characteristics. Herein, the SnS2 thin films are deposited by different techniques; chemical bath deposition (CBD), dip coating (DC) and spin coating (SC). The energy dispersive analysis of x-ray confirms the stoichiometry of the films deposited by these techniques. The x-ray diffraction showed hexagonal lattice structure of thin films. The morphology is studied by transmission electron, scanning electron and optical microscopy. The selected area electron diffraction exhibited ring patterns, confirming the polycrystalline nature of the deposited thin films. The atomic force microscopy showed presence of globular grains, hills and valleys on surfaces of thin films. The absorption spectra analysis showed the thin film possess direct optical bandgap of 2.39\xa0eV for CBD, 2.50\xa0eV for DC and 2.75\xa0eV for SC. Raman spectra of the as-deposited SnS2 thin films showed occurrence of A1g phonon mode at 314\xa0cm−1. The electrical transport properties assessment depicts the n-type semiconducting nature of deposited thin films. The as-deposited thin films showed good pulsed photoresponse for white light illumination intensities of 80 mW/cm2 and 120 mW/cm2.