Design and Simulation of Nitrogen-Doped Graphene (C2N) Using SCAPS-1D Technology: Brightening the Future of Solar Energy with Vision 2030

The present study introduces an advanced high-efficiency solar cell design that leverages nitrogenated holey graphene (C2N) as the absorber layer and a heavily doped p-CZT layer as an innovative back-surface field (BSF) material. Using the SCAPS-1D simulator, a previously reported cell structure (TCO/IGZO/C2N/back contact) with an efficiency of 18.22% was first reproduced and further enhanced by integrating Al and Pt as front and back contacts, respectively. A simple yet powerful numerical simulation in SCAPS enabled precise evaluation of how different physical parameters affect device performance. Building on these insights, a novel layered materials hetero-junction structure (Al/TCO/IGZO/C2N/CZT/Pt) was proposed. This device was proposed ans systematically optimized. This reveals that the CZT-BSF layer significantly boosts the performance—raising efficiency from 14.65 to 20.97%, while V_OC increased from 1.33 to 1.4044 V, J_SC , from 17.61 to 23.68 mA/cm2, and fill factor $$FF$$ from 84.50 to 89.08%. These findings highlight the strong potential of C2N-based structures for next-generation photovoltaic and optoelectronic technologies.