Advancement of stannite Cu₂CoSnS₄ thin films deposited by sol gel dip-coating route

Abstract

In this research effort, we synthesized copper-cobalt-tin-sulphur Cu2CoSnS4 (CCoTS) absorbers by sol–gel process associated with the dip-coating deposition technique on the ordinary glass substrates. We synthesized the impact of annealing temperature without utilization sulfurization on the structural, compositional, morphological, optical and electrical characteristics of layers annealed at 280, 300, 320 and 340 °C. CCoTS absorbers have been controlled by different control techniques included X-ray diffraction (XRD), Raman spectroscopic, Energy dispersive X-ray spectroscopy (EDS), Scanning electron microscopy (SEM), UV-vis spectroscopy and four-point probe technique (FPP). XRD patterns exhibited a polycrystalline structure with peaks agreeing to the (112), (204) and (312) directions and matching well with those of the pure stannite phase of CCoTS. The size of crystallites was found in the variety of 8.23-11.27 nm. Raman spectroscopic presented a peak at 332 cm−1 which is the signature of the pure stannite phase of CCoTS. EDS analysis measurements presented a close stoichiometric CCoTS thin films composition. SEM micrographs demonstrated an enhancement in films density and uniformity with annealing temperature rises. It was found that the band gap decreased from 1.72 to 1.5 eV with rising of annealing temperature. The sheet resistance was observed between 27.83 and 56.23 Ω/sq. These properties are quite interesting and can make the dip-coater CCoTS films as suitable novel absorbers for photovoltaic devices.

Correlation between the optical and microstructural characteristics and surface wettability transition of In2O3:Sn/ZnO nanostructured bilayer system for self-cleaning application

“…Increasing the annealing temperature gives atoms enough diffusion activation energy to occupy energetically beneficial sites in the material's crystal lattice. Therefore, crystallites become larger and surface energy decreases [30]. The ratio of height to diameter values in terms of the annealing temperature of ZnO nanorod-crystallite is presented in table 2, where H and W denote the height and diameter, respectively.…”

“…Daniel et al [38] and the GaN films by W. Wei et al [39]. These changes in the optical band gap can be attributed to the reduction of defects in the thin films by increasing the annealing temperature [30].…”