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 (mu c-Si:H) silicon solar cells. For 1-mu m-thick mu c-Si:H cells, the best current density is obtained at the period of 1.4 mu m, while a substantial enhancement in the external quantum efficiency is achievable in a wide range of period of 1-2 mu m. 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-mu m-thick and 2-mu m-thick mu c-Si:H cells, respectively.