Unlocking the solar potential: elevating open circuit voltage in kesterite CZTS thin film solar cells through cutting-edge SCAPS modeling

Kesterite-based CZTS thin-film solar cells are gaining recognition as a sustainable alternative to traditional photovoltaic technologies that rely on environmentally hazardous and costly absorber materials like c-Si, CdTe, and CIGS. The United Nations Sustainable Development Goals (UNSDGs) 7 (Affordable and Clean Energy) and 13 (Climate Action) are particularly relevant to CZTS technology. However, the efficiency of CZTS solar cells is currently constrained by the relatively low open circuit voltage (V oc ), which remains a primary barrier to their widespread adoption. This study uses cutting-edge SCAPS modeling to identify and address CZTS solar cell V oc constraints. The study optimizes acceptor, donor, and neutral defect states, shunt resistance, and interface states to improve device performance. Optimizing these parameters improves V oc and power conversion efficiency using rigorous numerical simulations. By optimizing defect states, the proposed MoS 2 /CZTS/CdS/ZnO structure achieved an improved open-circuit voltage (V oc ) of up to 1.10 V and an efficiency of up to 18.61%. This work makes solar energy more accessible and inexpensive by enhancing CZTS solar cell efficiency, especially in locations where conventional photovoltaic technologies are less practical due to economic or environmental constraints.