Low open circuit voltage (V-oc) values have been widely reported in kesterite Cu2ZnSnSe4 (CZTSe)-based thin film solar cells. So far, a complete understanding of the main sources of these low performances is far from clear. In this work, a theoretical model for CZTSe solar cell with record efficiency is presented. Among the different device loss mechanisms, trap-assisted tunneling recombination is introduced as the major hurdle to boost V-oc values. Detailed comparison of the simulation results to the measured device parameters shows that our model is able to reproduce the experimental observations. Finally, it is found that a further solar cell efficiency enhancement of up to 19.4% with an open circuit voltage close to 708 mV can be achieved by using more resistive CdS layers which is in contradiction to p-n junction behavior. In this way, a MIS performance is proposed to promote V-oc and efficiency values. As a result, this approach could help to solve at least one of the main issues of this technology. (C) 2016 Elsevier B.V. All rights reserved.