Comprehensive Design and Numerical Analysis of a Novel C ₂ N‐WS ₂ Tandem Solar Cell With Enhanced Photo‐Conversion Efficiency

Abstract The tandem solar cell (TSC) with top and bottom sub‐cells is able to absorb sunlight from visible to near infrared range and is promising for enhancing the photo‐conversion efficiency. We have proposed a TSC with a bandgap of 1.8 and 1.29 eV for carbon nitride (C 2 N) as a top sub‐cell and tungsten disulfide (WS 2 ) as a bottom sub‐cell absorber layer, respectively. In this research study, 1D solar capacitance simulation software (SCAPS‐1D) is used to analyze the open circuit voltage (V oc ), short circuit current (J sc ), fill factor (FF), and photo‐conversion efficiency (ƞ) of the top and bottom sub‐cell for the design of two‐terminal (2‐T) C 2 N‐WS 2 TSC. The current matching condition of J sc has been determined at the absorber layer thickness of 450 and 790 nm for the top and bottom sub‐cells, respectively. The TSC device parameters such as defect density and doping density have been optimized at 10 15 (C 2 N), 10 14 (WS 2 ) cm −3 , and 10 17 cm −3 (C 2 N and WS 2 ), respectively for achieving better performance of the proposed structure. The determined optimum values of V oc , J sc , ƞ, and FF are 2.38 V, 17.40 mA, 37.60%, and 90.78%, respectively. The present research paves the path for the realization of the high efficiency TSC.