PEDOT:PSS/n-Si Ultrathin Hybrid Silicon Solar Cells with a Solution Blunted Light-Trapping Texture

Reducing the thickness of crystalline silicon substrates is a key strategy to lower material costs in photovoltaics, yet it compromises light absorption and increases sensitivity to surface defects. This work introduces a low-temperature, solution-based blunting process to modify the random pyramidal texture on ultrathin n-Si substrates for PEDOT:PSS/n-Si hybrid silicon solar cells (HSSCs). The treatment optimizes the pyramid morphology, simultaneously enhancing light-trapping and improving the conformal contact of the spin-coated PEDOT:PSS hole-transport layer. This coordinated improvement mitigates interfacial recombination and parasitic absorption losses. Consequently, the power conversion efficiency (PCE) of 50 μm thick HSSCs increased from 8.88% to 11.39%, without introducing other functional layers or dopants. The thinned devices also demonstrated good mechanical robustness in flexible bending tests. This concise texture-blunting processing method presents a viable path for developing efficient, low-cost, and lightweight HSSCs.