Enhancement of the conversion efficiency of Cu2ZnSnS4 thin film solar cell through the optimization of some device parameters

One major factor affecting the performance of the kesterite Cu2ZnSnS4 (CZTS) thin film solar cell is its low open circuit voltage (Voc) which is often due to increased series resistance between the CZTS layer and the back-metal contact. In this work, numerical modeling as a tool has been employed to optimize the performance of CZTS thin film solar cell. A substrate structure was considered and simulation with our baseline parameters gave an efficiency of 6.74% which is comparable to reported experimental data. The introduction of p-MoS2 into the interface between the CZTS/Mo layers and the tuning of its bandgap enhanced the open circuit voltage. The increase in absorption coefficient of the CZTS layer increased the short circuit current (Jsc) while the optimization of the minority carrier lifetime further improved the open circuit voltage (Voc). The systematic optimization of the various device parameters gave an overall conversion efficiency of 18.05%.