The Cu/Cu2O nanocomposite as a p-type transparent-conductive-oxide for efficient bifacial-illuminated perovskite solar cells

Abstract

Inorganic–organic hybrid perovskite solar cells (PSCs) are considered as one of the promising devices for green energy. Bifacial-illuminated solar cells have been studied for many practical applications such as in wearable electronics and building window devices. p-Type transparent conductive oxides (TCOs) are highly desired for efficient bifacial-illuminated solar cells. However, the preparation of p-type TCOs usually requires high power sputtering and high temperature processes, and the thus-prepared TCOs can hardly be applied to PSCs due to the vulnerability of perovskites. In this study, p-type Cu/Cu₂O (CCO) composite films are developed for bifacial-illuminated PSCs. The p-type CCO composite films can be easily prepared by sputtering at room temperature and do not damage the underlying organic materials Spiro-OMeTAD and perovskites. With a reduced film thickness of about 12 nm, the p-type CCO films can be employed as transparent conductive films in PSCs. The power conversion efficiencies (PCEs) of 14.10% and 9.37% have been achieved for bifacial PSCs illuminated via the fluorine-doped tin oxide (FTO) and CCO sides, respectively. In addition, the CCO films are stable under ambient conditions and can serve as a protection layer for PSCs. Therefore, ultra-thin p-type CCO films are promising candidates for applications in bifacial-illuminated, efficient and stable PSCs under ambient conditions.