Comparative Study of CZTS Solar Cell with Different Buffers and BSF Layer

Solar cell based on kesterite structured compound semiconductor Copper-Zinc-Tin-Sulphide (CZTS) has been attracting the researchers due to its high possibility in the photovoltaic world. For performance enhancement of the baseline structure CZTS solar cell, the type of cells utilized in this work is Al:ZnO/CdS(In2S3/Zn(O,S))/CZTS/SnS/Mo. In this work, a comparison on the performance of CdS, In2S3 and Zn(O,S) buffer layers is performed to find a suitable buffer layer along with insertion of a SnS back surface field (BSF) using Solar Cell Capacitance Simulator (SCAPS) 3.3.0.7. Here, the effect of absorber thickness variation, buffer thickness variation, absorber doping density and absorber defect density variation on cell performance have been analyzed. An efficiency of 16.61% has been achieved with only 1μm thickness of CZTS absorber layer. Among the three buffer layers, Zn(O,S), with an optimum efficiency of 16.60%, has proved to be more suitable than the others (with VOC = 829mV, JSC = 29.67 mA/cm
²
and fill factor = 67.50%) and In2S3 shows drastic change in performance parameters.