Enhanced recovery of light-induced degradation on the micromorph solar cells by electric field

Abstract

The recovery of light-induced degradation of the tandem micromorph solar cell by applying reverse bias is compared with the single-junction amorphous silicon solar cell. The illuminated current density-voltage characteristics and external quantum efficiency show that the degradation of both the micromorph and the amorphous silicon cells can be recovered by applying sufficient reverse bias. The micromorph cell was recovered at smaller reverse bias than amorphous silicon cell. The abundant H in the microcrystalline silicon bottom cell of the micromorph cell can act as a reservoir to repair the defects in the amorphous silicon top cell at the reverse bias. This is responsible for small recovery bias of tandem cells.