Photonic nanovoids for tailored optoelectronic response in silicon solar cells

Abstract As crystalline silicon (c‐Si) solar cells become thinner to reduce cost and weight, the optical design principles that govern light trapping (LT) must evolve. Conventional texturing remains effective in thick wafers but loses practicality as thickness decreases, whereas thin‐film nanophotonics relies on guided‐mode coupling mechanisms incompatible with wafer‐scale constraints. This disconnect exposes the need for a thickness‐aware understanding of LT in silicon. These challenges motivate a manufacturing‐aware unification of optical and drift‐diffusion transport that clarifies how photonics gains translate into device‐level performance across silicon thicknesses. Here, novel high‐index honeycomb nanovoids are patterned onto c‐Si absorbers, preserving electronic quality while enabling strong optical gains from ultra‐thin to wafer‐scale devices. Optics is here coupled with drift‐diffusion and complemented with Fourier‐space descriptors, together with an unprecedented angle‐resolved light scattering analysis to quantify lattice‐mediated light coupling and energy redistribution. On 1‐μm c‐Si absorbers, the nanovoids are predicted to enhance photocurrent by ∼60% and near double efficiency relative to planar counterparts, sustaining angular gains up to 40°. Experimentally realized nanovoids onto interdigitated back‐contact c‐Si cells, they deliver ≈51% efficiency gains. These results demonstrate that front‐coated photonic nanovoids enable scalable, electrically benign LT across thickness regimes, unlocking a viable path toward ultrathin, high‐performance silicon photovoltaics, grounded in a holistic full‐device design.