Thin-Film Silicon Solar Cells on 1-D Periodic Gratings With Nonconformal Layers: Optical Analysis

Design of 1-D submicrometer periodic gratings aimed at the enhancement of the short-circuit current density in thin-film silicon solar cells is investigated. A rigorous full-wave analysis is carried out to determine the absorption in amorphous (a-Si:H) and microcrystalline (μc-Si:H) silicon solar cells on substrates with gratings featuring different geometrical characteristics. Maximal photocurrent densities J_ph are evaluated in both superstrate (p-i-n) and substrate (n-i-p) configurations, taking into account the nonconformal growth of the layers on the gratings. The J_ph relative to that of corresponding flat solar cells was found to be 1.34, 1.24, 1.23, and 1.38 times higher for p-i-n a-Si:H, μc-Si:H-based structures, and n-i-p a-Si:H, μc-Si:H based structures, respectively.