Physical and Dielectric Properties of Ni-Doped In₂S₃ Powders for Optical Windows in Thin Film Solar Cells

This paper reports the effect of Nickel (Ni) on indium sulfide (In₂S₃) powder. This work presents a systematic study of the physical and dielectric properties of In_2-xS₃Ni_x powders with 0, 2, 4, and 6 at.% of nickel. Doped and undoped samples were investigated by X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy, thermal gravimetric analysis, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and impedance spectroscopy. XRD patterns revealed that each In_2-xS₃Ni_x composition was crystalline, which was also confirmed by the FTIR results. The presence of Ni in the samples was confirmed by energy dispersive spectroscopy (EDS). The Raman studies show different peaks related to the In₂S₃ phase and do not reveal any secondary phases of In-Ni and Ni-S. The SEM images of the undoped and Ni-doped In₂S₃ samples indicated a correlation between dopant content and the surface roughness and porosity of the samples. The impedance analysis indicated semiconductor behavior present in all samples, as well as a decrease in resistance with increasing Ni content. This work opens up the possibility of tailoring the properties and integrating Ni-doped In₂S₃ nanocomposites as thin film layers in future solar cells.