Exploring the structural, optical, and optoelectrical characteristics of p-type CuNiBiS₃ thin films prepared by the chemical deposition method

The authors use chemical bath deposition to synthesize novel copper-nickel bismuth sulfide (CuNiBiS₃) thin films on glass slides. The X-ray diffraction measurements detected the crystal structure of the CuNiBiS₃ layers, which display orthorhombic structures for these films. The structural indices of the CuNiBiS₃ layers were determined by the Williamson–Hall relationship. Furthermore, the Energy dispersive spectroscopy of the CuNiBiS₃ layers refers to these layers having a stoichiometric composition. On the other side, the linear optical indices of the CuNiBiS₃ layers were determined depending on the transmittance and reflectance data. The energy gap analysis indicates that the CuNiBiS₃ layers have a direct optical transition. The energy gap values of the CuNiBiS₃ layers were reduced from 1.43 to 1.31 eV by enlarging the thickness of these layers. These layers’ nonlinear, optoelectrical, and dispersion indices, like the static high-frequency dielectric constant, optical conductivity, dispersion energy, nonlinear refractive index, and optical carrier concentration, were improved by boosting the layer thickness. Moreover, the hot probe test revealed that CuNiBiS₃ layers tended to acquire p-type characteristics.