| Abstract: | The newly developed PbN(CN)2]2 additives have been demonstrated for enhancing efficiency from 14.7% to 17.4% and from 15.5% to 18.2% for conventional (FTO/TiO2 as the substrate) and inverted (FTO/NiOx as the substrate) MAPbI3 perovskite solar cells (PVSCs), respectively. Different from many effective additives of PVSCs, PbN(CN)2]2 provides the first visual evidences (colors changing) of additives participating in the solution adduct of MAPbI3 precursors. Further experimental results reveal that the PbN(CN)2]2 additives slowdown the formation process of the MAPbI3 crystallite thin film, of which the grain size reaches up to 900 nm with 0.2 M concentration of PbN(CN)2]2 additives in the MAPbI3 precursor solutions (1 M), accordant with the optimal concentration of PbN(CN)2]2 additives in enhancing efficiency of MAPbI3 PVSCs. We understand the role of PbN(CN)2]2 additives in MAPbI3 PVSCs through color photos (of precursor adduct solution and the adduct solid isolated from solutions), infra-red (of adduct solid isolated from solution), UV–visible absorption, photoluminescence, static and time-dependent powder X-ray spectroscopies. |
