Enhanced light-trapping in laser-crystallised silicon thin-film solar cells on glass by optimised back surface reflectors

Abstract

This paper presents enhanced light-trapping (LT) in liquid-phase crystallised silicon (LPC Si) thin-film solar cells on glass superstrate by optimised back surface reflectors (BSRs). In the LPC Si film on SiOx buffer layer (without anti-reflection effect), the white paint BSR is found to increase the long wavelengths light absorption, with potential short-circuit current density (Jsc) of 23.6mA/cm2 (15.7% enhancement, compared to the planar reference film). Ag plasmonic nanoparticles (NPs) reflector with surface coverage of 47.9% and average diameter of 196.3nm shows almost similar absorption enhancement as the white paint but with slightly lower potential Jsc (23.3mA/cm2, or 14.2% enhancement). In the LPC Si solar cells, the average open-circuit voltage (Voc) and pseudo fill factor (pFF) are not deteriorated by the presence of the Ag NPs on the Si surface. When combining the Ag NPs, white paint and anti-reflection foil, Jsc up to 23.3mA/cm2 (18.9% enhancement compared to the planar reference cell) is achieved.