Thin films of binary nickel sulphide (NiS) and zinc-doped ternary nickel sulphides (Ni1−xZnxS, where x = 0–1) were effectively produced by the chemical bath deposition method, and their potential use in photovoltaics were investigated. Dopant inclusion did not change the crystal structure of NiS, according to the structural analysis of the synthesized samples. They are appropriate for solar cell applications since the morphological study verified the crack-free deposition. Optical research revealed that the deposited thin films had refractive index (n) ranges between 1.25 and 3.0, extinction coefficient (k) ranges between 0.01 and 0.13, and bandgap values between 2.25 and 2.54 eV. Overall findings indicated that doping is a useful method for modifying the composition, and therefore, the structural and morphological characteristics of NiS thin films, to enhance their optoelectronic behavior.
