Nanoimprint lithography of textures for light trapping in thin film silicon solar cells



Nanoimprint lithography (NIL) is a versatile and commercially viable technology for fabrication of structures for light trapping in solar cells. We demonstrate the applicability of NIL in thin film silicon solar cells in substrate configuration, where NIL is used to fabricate a textured rear contact of the solar cells. We applied random structures, based on the natural texture of SnO/F grown by APCVD, and designed 2D periodic structures and show that for single junction µc-Si cells these textured rear contacts lead to an increase of Jsc of more than 40% in comparison to cells with flat rear contacts. Cells on optimized periodic textures showed higher fill factors which can be attributed to reduced microcrack formation, leading to less shunting in comparison to cells on random textures.