Efficient light trapping nanopyramid structures for solar cells patterned using UV nanoimprint lithography

In this paper, we demonstrate that periodic inverted nanopyramid structures can enhance the power conversion efficiency of monocrystalline silicon solar cells by minimizing reflections, improving light trapping process in addition to its self-cleaning functionality. The periodic inverted nanopyramid structures were fabricated on monocrystalline silicon solar cell surfaces using a UV nanoimprint lithography. By introducing inverted nanopyramid structures on the front side of the monocrystalline silicon solar cells, the power conversion efficiency was improved by 11.73% compared to identical solar cells without the texturing. The inverted nanopyramid coating decreased the reflectance and increased the external quantum efficiency over a broad wavelength range. Moreover, the surface of the solar cells exhibited hydrophobic properties due to increased contact angle caused by the nanostructure patterns and the self-assembled monolayer coating. The enhanced hydrophobicity provided the solar cells with an added self-cleaning functionality. These results suggest that the periodic inverted nanopyramid structures has high potential in improving the performance of silicon solar cells and may be applied to different types of solar cells.