Optimizing solar performance of CFTSe-based solar cells using MoSe as an innovative buffer layers.

In this study, we explore the photovoltaic performance of an innovative high efficiency heterostructure utilizing the quaternary semiconductor CuFeSnSe (CFTSe). This material features a kesterite symmetrical structure and is distinguished by its non-toxic nature and abundant presence in the earth's crust. Utilizing the SCAPS simulator, we explore various electrical specifications such as short circuit current (J), open circuit voltage (V), the fill factor (FF), and power conversion efficiency (PCE) were explored at a large range of thicknesses, and the acceptor carrier concentration doping (N). Our results demonstrate that optimized parameters yield a remarkable PCE of 26.47%, accompanied by a V of 1.194 V, J of 35.37 mA/cm, and FF of 62.65% at a CFTSe absorber thickness of 0.5 μm. Furthermore, the performance of the photovoltaic cell is assessed for the defect levels in the CFTSe absorber and MoSe buffer layers. Results indicate that deep defect levels above 1 × 10 cm lead to a decrease in J. The study also investigates the effect of operating temperature on cell performance within the 300-500 K range. A notable decline in V is observed, likely due to an increase in saturation current, suggesting an interaction between temperature and cell behavior. In this work, we propose a practical CFTSe-based structure that replaces conventional buffer layers, such as CdS, with MoSe TMDC as a promising alternative buffer layer, paving the way for more sustainable solar technology.