TCAD Driven Light-Trapping Enhancement in Silicon Photovoltaics through Engineered Nanohole Geometries

Nanohole (NH) patterning in silicon has been widely explored as an effective light-trapping strategy for photovoltaic devices; however, the extent to which optical enhancement translates into electrical performance improvement remains strongly limited by carrier recombination and doping-dependent transport effects. In this work, a coupled optical-electrical TCAD framework is employed to systematically investigate the impact of engineered silicon nanohole geometries on both light absorption and device-level performance. Nanohole thicknesses ranging from 100 to 400 nm and acceptor doping concentrations from 1015 to 1019 cm – 3 are analyzed through weighted optical efficiencies, carrier generation, recombination dynamics, and current-voltage characteristics. The results show that increasing nanohole thickness significantly enhances light trapping, with weighted absorption efficiency exceeding 45 % for a nanohole thickness of 400 nm and up to ~ 40 % improvement in optical absorption compared to a planar reference structure. Electrical simulations reveal a clear efficiency optimum at an acceptor doping concentration of approximately 1018 cm − 3, beyond which Shockley-Read-Hall recombination degrades carrier collection. At this optimal operating point, the 400 nm nanohole-based device achieves a significant PCE enhancement relative to the planar thin-film cell. The study demonstrates that maximum efficiency is achieved through a balanced co-optimization of nanohole geometry and doping concentration, and establishes TCAD-based quantitative design guidelines for a nanostructured silicon solar cell beyond optical-only optimization approaches [1-3, 6-9].