Beijing Key Laboratory of Novel Thin-Film Solar Cells , North China Electric Power University , Beijing 102206 , P. R. China.
Key Laboratory of Photovoltaic and Energy Conservation Materials , Chinese Academy of Sciences , Hefei , Anhui 230088 , P. R. China.
ACS Appl Mater Interfaces. 2018 Jul 18;10(28):23466-23475. doi: 10.1021/acsami.8b07422. Epub 2018 Jul 6.
Organic-inorganic perovskite solar cells (PSCs) are one of the most attractive and efficient burgeoning thin-film photovoltaics. The perovskite films have been fabricated via lots of deposition methods, but these laboratory-based fabrication methods are not well-matched with large-area manufacture. Herein, spray coating as a deposition technique was explored to prepare perovskite films and break the bottleneck that plagued large-scale production. However, it is hard to reduce the notorious "coffee-ring effect" during the process of spraying perovskite films especially in a one-step spraying method. Thus, the vapor-assisted spraying method (VASM), namely, fabricating perovskite films through a vapor-solid in situ reaction between CHNHI vapor and sprayed PbI films, was creatively applied to the preparation of dense and uniform perovskite films. The surfaces of the sprayed PbI films were optimized by adjusting the wettability, viscosity, and contact quality via various methods such as the selection of solvent, solution concentration, and substrate temperature to inhibit the capillary flow and release the pinning contact line. The application of a component solvent could effectively crush the dense structure of the PbI film, optimizing the morphology of PbI films and reducing the influence of the coffee-ring effect. Integrating the above aspects, the optimized PbI films could form uniform perovskite films via an in situ reaction, and a best power conversion efficiency of 17.56% was achieved for planar structure PSCs, which is high among the PSCs fabricated by the spraying method. In addition, the VASM could be applied in the actual conditions for mass production, exhibiting excellent optical and electrical properties and paving the way of the commercialization of PSCs.
有机-无机钙钛矿太阳能电池（PSCs）是最有吸引力和效率最高的新兴薄膜光伏材料之一。钙钛矿薄膜已经通过多种沉积方法制备，但这些基于实验室的制备方法与大面积制造不匹配。在此，喷雾涂覆作为一种沉积技术被探索用于制备钙钛矿薄膜，并打破困扰大规模生产的瓶颈。然而，在喷涂钙钛矿薄膜的过程中，很难减少臭名昭著的“咖啡环效应”，特别是在一步喷涂方法中。因此，创造性地应用蒸气辅助喷涂法（VASM），即通过 CHNHI 蒸气和喷涂 PbI 薄膜之间的固-固原位反应来制备致密和均匀的钙钛矿薄膜。通过选择溶剂、溶液浓度和基底温度等各种方法来优化喷涂 PbI 薄膜的表面润湿性、粘度和接触质量，以抑制毛细流动并释放钉扎接触线，从而优化喷涂 PbI 薄膜的表面。应用辅助溶剂可以有效地破坏 PbI 薄膜的致密结构，优化 PbI 薄膜的形态，并减少咖啡环效应的影响。综合以上各方面，优化后的 PbI 薄膜可以通过原位反应形成均匀的钙钛矿薄膜，平面结构 PSCs 的最佳功率转换效率达到 17.56%，这在喷涂法制备的 PSCs 中是较高的。此外，VASM 可以应用于实际的大规模生产条件，表现出优异的光学和电学性能，为 PSCs 的商业化铺平了道路。
