Ni doping in CZTS solar cells: a path to enhanced photovoltaic performance

The present communication explores the optical, structural, compositional, and electrical properties of Copper Zinc Tin Sulfide (CZTS) and Nickel (Ni)-CZTS solar cells. A microwave-based synthesis method has been employed to synthesize CZTS and Ni-doped CZTS powders. X-ray diffraction and Raman scattering spectroscopy have confirmed the monophase kesterite crystal structure of CZTS and Ni-CZTS. Optical absorption spectroscopy of films in the UV–Visible range displays a strong absorption coefficient of more than \(10^{4} {\text{cm}}^{ - 1}\). In response to Ni doping, the optical band gap energy of CZTS decreased to 1.41 eV from 1.5 eV. In both samples, positive Hall coefficients were detected, confirming the presence of p-type conductivity. This study aims to determine the effects of Ni-CZTS incorporation on the performance of FTO/CZTS/CdS/ZnO/Ag solar cells. The introduction of Ni-CZTS between CZTS and CdS resulted in optimum alignment and higher efficiency. 5% Ni doping concentration is found to be the optimum doping concentration, resulting in \(J_{sc} = 32.5\;{\text{mA}}/{\text{cm}}^{2}\), \(V_{{{\text{oc}}}} = 0.541\;{\text{V}}\), \({\text{FF}} = 31\%\) and the efficiency is 5.4%.