Thorough investigation of the optical, electrical and thermal properties of Cu3Se2 thin film deposited by chemical bath deposition

Abstract

Recently, metal chalcogenide thin films have gained utmost significance across various industries attributed to their exceptional versatility and efficiency in advancing future electronics, optoelectronics and energy conversion devices. In this work, the formation of a copper selenide (Cu3Se2) thin film is accomplished through the utilization of chemical bath deposition approach. The energy dispersive analysis of X-ray and X-ray photoelectron spectroscopy confirmed the chemical composition stoichiometry for the as-deposited Cu3Se2 thin film. X-ray diffraction analysis conclusively validates the tetragonal unit cell structure. The homogenous and crack-free film deposition is verified employing optical microscopy, scanning electron microscopy, and atomic force microscopy analysis. The crystalline character of the thin film is ascertained by the evident appearance of lattice fringe patterns in high-resolution transmission electron microscopy along with the distinctive spot patterns perceived in the selected area electron diffraction pattern. The optical reflectance spectrum revealed a direct bandgap of 1.77 eV. The Raman spectrum exhibited a solitary peak at 259 cm−1 that corresponds to the Ag1 vibrational mode of the Cu-Se phase. The comprehensive electrical transport property for the as-deposited thin film is accomplished through the control assessment of temperature-dependent d.c. electrical resistivity and photoresponse current-voltage profiles. The investigation of the thermal decomposition of the Cu3Se2 thin film is conducted via thermogravimetry, utilizing the non-mechanistic Kissinger method to extract kinetic parameters from the thermal dataset. The acquired outcomes are thoroughly examined in this manuscript.