Investigation of textured back reflectors with periodic honeycomb patterns in thin-film silicon solar cells for improved photovoltaic performance

Periodically textured back reflectors with a honeycomb dimple pattern are investigated for improving the infrared response and conversion efficiency in substrate-type microcrystalline (μc-Si:H) silicon solar cells. For 1-μm-thick μc-Si:H cells, the best current density is obtained at the period of 1.4 µm, while a substantial enhancement in the external quantum efficiency is achievable in a wide range of period of 1–2 µm. In addition, photocurrent of the cells is improved with increasing the aspect ratio of the honeycomb textures. As a result of a high open-circuit voltage and fill factor, as well as the improved current densities, high conversion efficiencies of 9.4% and 9.9% are realized in the 1-µm-thick and 2-µm-thick μc-Si:H cells, respectively.