Silicon Nanotexture Surface Area Mapping Using Ultraviolet Reflectance

The enhanced surface area of silicon nanotexture is an important metric for solar cell integration as it affects multiple properties including optical reflectance, dopant diffusion, and recombination. Silicon typically characterized by its surface-area-to-projected-area ratio or factor (EAF). However, traditional approaches measuring EAF provide limited statistics, making correlation studies difficult. In this article, silicon's dominant ultraviolet reflectance peak, R(E2), which very sensitive to etching, applied spatial mapping. A clear decay between R(E2) shown textures created using reactive ion etching metal catalyzed chemical etching. This R(280 nm) mapping yield accurate, high-resolution full-wafer nanotextures. also be enough correlate the impact variation on post-diffusion sheet resistance. Finite-difference time-domain simulations several nanoscale pyramid confirm a band versus EAF, consistent with our measurements. We suggest that may prove useful other applications where important.