Analysis of dopant concentration effect on optical and morphological properties of PVD coated Cu-doped Ni3S2 thin films

Abstract

Current research has commenced the synthesis of Nickel-Diethyl dithiocarbamate Ni (S2CN (Et) 2) n]) and Copper diethyldithiocarbamate Cu (S2CN(Et)2) complex by single source precursor method. These complexes were utilized for deposition of pure and Cu-doped Ni3S2 thin films on glass substrate by physical vapor deposition technique. FTIR peaks of Copper and Nickel complex confirmed the formation of dithiocarbamate complex depicted by vibrational frequencies of M–S bond. Thermo-gravimetric analysis (TGA) of Nickel diethyl dithiocarbamate depicted decomposition of complex into corresponding metal sulphides. Different phases were observed by XRD in which predominant phase is Ni3S2 and crystalline size was about 90.8 nm calculated by Debye Scherrer equation. Fabrication of thin film is confirmed by UV–vis-Spectroscopy indicating the band gap of 2.1 eV for pure nickel sulphide which decreases to an appreciable extent of 1.89 eV for 6% doping of Copper while a slight decrease (i.e., 1.63 eV) upon 10% doping. The SEM showed homogeneous covering with Ni3S2 spherical particles at a few distance apart and grain size was 450 μm. Energy dispersive X-ray (EDX) have shown the proper deposition of Nickel Sulphide on glass substrate with subsequent doping of Copper. To the best of our knowledge, optical and structural analysis of PVD deposited doped and undoped Ni3S2 thin films were examined for the first time in this study.