Rear texturing for light-trapping in laser-crystallised silicon thin-film solar cells on glass

Abstract

This paper presents optimisation of rear Si texturing by KOH-based solution for enhanced light-trapping in liquid-phase crystallised Si thin-film solar cells on glass. Texturing with 3 µm Si removal exhibits the largest absorption enhancement (compared with 1 and 2 µm Si removal) due to the enhanced light scattering by the rear pyramidal features. In the solar cells with SiOx/SiNx/SiOx buffer layer (with anti-reflection effect), the Jsc is found to increase from 20.4 (planar reference) to 22.6 mA/cm2 (10.8% enhancement) with the optimised rear Si texturing. The Voc and pFF are not degraded. After incorporating white paint back surface reflector and front anti-reflection foil to the rear-textured solar cells, Jsc up to 25.4 mA/cm2 (24.5% relative enhancement) is achieved.