Surface Passivation of Perovskite Solar Cells Toward Improved Efficiency and Stability

The advancement of perovskite solar cells(PVSCs)technology toward commercialized promotion needs high efficiency and optimum stability.By introducing a small molecular material such as tetratetracontane(TTC,CH(CH)CH)at the fullerene(C)/perovskite interface of planar p-i-n PVSCs,we significantly reduced the interfacial traps,thereby suppressing electron recombination and facilitating electron extraction.Consequently,an improved efficiency of 20.05% was achieved with a high fill factor of 79.4%,which is one of the best performances for small molecular-modified PVSCs.Moreover,the hydrophobic TTC successfully protects the perovskite film from water damage.As a result,we realized a better long-term stability that maintains 87% of the initial efficiency after continuous exposure for 200 h in air.