摘要
The fast-growing procedure （FGP） provides a simple, high-yield and lead （Pb）-release free method to prepare perovskite films. In the FGP, the ultra-dilute per- ovskite precursor solution is drop-cast onto a hot （-240℃） substrate where a perovskite film grows immediately ac- companied by the rapid evaporation of the host solvent. In this process, all the raw materials in the precursor solution are deposited into the final perovskite film. The potential pollution caused by Pb can be significantly reduced. Proper- ties of the FGP-processed perovskite films can be modulated by the precursor composition. While CH3NH3CI （MACI） affects the crystallization process and leads to full surface coverage, CH（NHz）2I （FAI） enhances the thermal stability of the film. Based on the optimized precursor composition of PbI2.（1-x）FAI.xMACI, x=0.75, FGP-processed planar het- erojunction perovskite solar cells exhibit power conversion efficiencies （PCEs） exceeding 15% with suppressed hysteresis and excellent reproducibility.
快速成膜工艺提供了一种简单、高产率、无铅释放的钙钛矿薄膜制备方法.在这一方法中,低浓度的钙钛矿前驱体溶液被滴到240℃的热衬底上,伴随着溶剂在高温条件下的迅速挥发,钙钛矿在衬底表面迅速结晶,生长成一层薄膜.在此过程中,所有含铅的原材料都被沉积到钙钛矿薄膜中,含铅原材料的浪费和铅释放导致的污染都被显著降低.这种方法制备的钙钛矿薄膜的性质可以由前驱体溶液的组分调节.CH_3NH_3Cl(MACl)可以调节结晶过程,有助于提高薄膜表面覆盖率.CH(NH_2)_2I(FAI)有助于提高钙钛矿薄膜的热稳定性.当前驱体组分为PbI_2·(1-x)FAI·xMACl,x=0.75时,快速成膜工艺制备的钙钛矿膜达到最优化性质,由此制备的平面结太阳电池可以实现超过15%的能量转换效率,迟滞现象很小,并且重复性良好.
基金
financially supported by the National Basic Research Program of China (973 Program) (2015CB932203)
the National Natural Science Foundation of China (61377025, 91433203, and 11121091)
the Young 1000 Talents Global Recruitment Program of China
supported by the US Office of Naval Research under contract N00014-15-1-2244
the support from the US National Science Foundation (DMR-1305913 and OIA-1538893)
