关键词: 钙钛矿太阳电池, 界面能量, 2-巯基嘧啶, 路易斯酸碱理论

Abstract: It was investigated that 2-mercaptopyrimidine （2-MP） passivated the interface between the perovskite layer and hole transport layer of a triple cation perovskite solar cell, which improved the photoelectric properties of the film and the device. Steady-state and time-resolved photoluminescence fluorescence spectrum characterization results showed that non-radiative recombination of the passivated perovskite film was suppressed. In addition, the work function characterizations by KPFM illustrated that the energy level of PVK/2-MP/Spiro matched better than that of PVK/2-MP/Spiro, that is beneficial to suppress carrier recombination and enhance open-circuit voltage. After passivation, the hydrophobicity of the film was enhanced which is helpful to block water vapor erosion and improve stability. The open-circuit voltage dependence on light intensity shows that 2-MP effectively passivates the interface defects and suppress the non-radiative recombination of carriers. The J-V test showed that the photoelectric performance of the device was significantly improved with passivation, the open-circuit voltage was up to 1.133 V, and the efficiency was up to 21.66%. Moreover, the stability of the optimized device was significantly improved. After 97 days of storage in nitrogen, the efficiency maintained 90% of the initial efficiency.

Key words: perovskite solar cells, interfacial energy, 2-mercaptopyrimidine, Lewis acids and bases