Enhancement in performance of Copper Zinc Tin Sulphide (Cu2ZnSnS4) based thin film solar cell has been proposed using SCAPS-1D simulation program. The proposed cell structure Cu2ZnSnS4 (CZTS) included CdS as buffer layer, CZTS as absorber layer, and n-doped ZnO as window layer. On these layers, the open circuit voltage (Voc), short circuit current density (Jsc), fill factor (FF), conversion efficiency (η), and quantum efficiency (QE) have been examined at the effect of temperature (280–400 K), thickness (500–4000 nm) series (1 Ω cm2) and shunt (1000 Ω cm2) resistances. The performance of proposed cell has been improved in terms of QE, Jsc, Voc, η, and QE with respect to the standard Mo/Cu2ZnSnS4/CdS/ZnO solar cell. However, by optimizing, we have successfully achieved the enhancement in efficiency of 19.64%, while Jsc, Voc, and FF are 24.22 mA cm−2, 0.9489 V, and 86.13% were observed, respectively.