Preparation of Nickel Sulfide Thin Films and Nanocrystallites Using Nickel Furfuraldehyde Thiosemicarbazone as Single-Source Precursor

Abstract

Nickel furfuraldehyde thiosemcarbabazone adduct of the type, NiCl2(L)2 (L = furfuraldehyde thiosemicarbazone) was synthesized by the reaction between nickel dichloride hexahydrate and furfuraldehyde thiosemicarbazone in 1:2 stoichiometry. The resulting compound was characterised by elemental analysis, IR, 1H and 13 C{1H} NMR spectral data. It was further used as a single-source precursor for the deposition of nickel sulfide thin films by aerosol assisted chemical vapour deposition (AACVD) technique and the nickel sulfide nanocrystallites by pyrolysis and solvothermal decomposition methods. The thin films obtained were characterised by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis by X-rays (EDAX) and atomic force microscopy (AFM). The nanocrystallites obtained were also characterized by XRD, EDAX as well as transmission electron microscopy (TEM). The SEM images of the thin films show formation of different morphologies of nickel sulfide, i.e. nanoball-like, nanowires to flower-like depending on the growth temperature. The mechanism for the variation of the morphology with the growth temperature has been proposed. The XRD of the nanocrystallites obtained matches with the hexagonal phase of nickel sulfide and the TEM images show formation of 10-50 nm spherical nano-crystals.