Ecofriendly high-performance low-cost Cu₂ZnSnSe₄ solar cells: Experimental characterization and SCAPS-1D simulation

Cu₂ZnSnSe₄ (CZTSe) is a promising low-cost and ecofriendly p-type semiconductor for solar cells. However, CZTSe solar cells are have shortcomings, as they typically involve hazardous CdS-buffer layers. Costly dopant elements Ag and/or Ge are also normally used. This study aims at producing efficient, ecofriendly and low-cost solar cells. The Cd-, Ag- and Ge-free configuration metal/MoSe₂/CZTSe/ZnSe/i-ZnO/ZnO-Al/metal is proposed. CZTSe film is prepared by the facile and low-cost sol-gel method, and characterized by elemental analysis, optical-absorption spectra, surface morphology, surface profiling and wettability. The cell is simulated by SCAPS-1D. Optimal CZTSe-layer thickness is 2.5 μm with optimized doping concentration 5 × 10¹⁶ cm⁻³. With these parameters, the cell exhibits an open-circuit potential 0.56 V, a short-circuit potential 47.33 mA/cm² and a fill factor 73.82 %. With a cell conversion efficiency 19.5 %, the proposed cell outperforms earlier CZTSe cells in terms of cost and environmental friendliness. This opens new research inroads toward improved CZTSe-based solar cells.