17.6 percent Efficient Tricrystalline Silicon Solar Cells with Spatially Uniform Texture

摘要

Up to now solar cells fabricated on tricrystalline Czochralski-grown silicon (tri-Si) have shown relatively low short-circuit current densities of about 31-33 mA/cm~2 because the three {110}-oriented grains cannot effectively be textured by commonly used anisotropic etching solutions. Iii this work, we have optimised a novel chemical texturing step for tri-Si and integrated it successfully into our solar cell process. Metal/insulator/semiconductor-contacted phosphorus-diffused n~+p junction silicon solar cells with a silicon-dioxide-passivated rear surface and evaporated aluminium contacts were manufactured, featuring a spatially uniform surface texture over all three grains on both cell sides. Despite the simple processing sequence and cell structure, an independently confirmed record efficiency of 17.6 percent has been achieved. This excellent efficiency is mainly due to an increased short-circuit current density of 37 mA/cm~2 obtained by substantially reduced reflection and enhanced light trapping.