Optimizing solar performance of CFTSe-based solar cells using MoSe2 as an innovative buffer layers

Abstract

In this study, we explore the photovoltaic performance of an innovative high efficiency heterostructure utilizing the quaternary semiconductor Cu₂FeSnSe₄ (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_sc), open circuit voltage (V_oc), the fill factor (FF), and power conversion efficiency (PCE) were explored at a large range of thicknesses, and the acceptor carrier concentration doping (N_A). Our results demonstrate that optimized parameters yield a remarkable PCE of 26.47%, accompanied by a V_oc of 1.194 V, J_sc of 35.37 mA/cm², 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 MoSe₂ buffer layers. Results indicate that deep defect levels above 1 × 10¹⁷ cm^{- 3} lead to a decrease in J_sc. The study also investigates the effect of operating temperature on cell performance within the 300-500 K range. A notable decline in V_oc 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 MoSe₂ TMDC as a promising alternative buffer layer, paving the way for more sustainable solar technology.