CZTS/ZnS solar cell modelled with SCAPS-1D simulation program

Abstract

In the study, zinc sulphide (ZnS) thin films compound of the II–VI group were fabricated by known as ultrasonic spray pyrolysis technique (USP) on glass substrates. Optical properties of these films were characterized by using ultraviolet–visible (UV–Vis) spectrophotometry. Measurements of Ultraviolet–visible spectroscopy point out that the absorbance and direct band gap of zinc sulphide samples annealed at diverse ambient is improved. Energy band gap of the obtained ZnS thin film found to be 3.75, 3.66, 3.58, 3.68 and 3.70 eV for ZnS-as grown, ZnS-N2, ZnS-air, ZnS-H2S 500, ZnS-H2S 550 films, respectively. ZnS thin film, which is annealed H2S:Ar ambient at 550 C, has higher absorption and extinction coefficient compared to other thin films. Refractive indices were calculated with Moss and Herve&Vardamme relations. ZnS thin film, which is annealed at air ambient has the highest refractive index, ZnS thin film, which is not annealed has the lowest one. Au/CZTS/ZnS-500&ZnS-550/i-ZnO/AZO solar cells that is modelled by SCAPS simulation. ND value from 2.1016 to 1.1017 cm-3 , VOC, JSC and n values, which decreased from 0.711 V to 0.576 V, from 15.44 mAcm-2 to 10.78 mAcm-2 , from 7.48% to 4.47%, respectively. SnO2 intermediate layer, is placed between CZTS and ZnS layers, caused more charge separation at the two interfaces and increased VOC and efficiency of the solar cell.