柔性钙钛矿大面积成膜过程中的成核结晶机制研究及调控

Due to the solution processibility, perovskite solar cells (PSCs) could be fabricated with low cost. Flexible PSCs have advantages of flexibility and light weight, more suitable for the new photovoltaics products that require light weight. Aiming for the commercialization, besides addressing the stability issue, we need develop methods to fabricate large scale perovskite thin films. However, few efforts have been devoted to the study of the mechanism of the nucleation and crystal growth of the perovskite during the film formation, but more on the techniques of small area film fabrication. In this project, we focus on the investigation of the mechanism of the nucleation and crystal growth of the perovskite during the film formation and the effect of the different cations, anions and substrate materials on the perovskite crystals formation and growth. With the above research results, it is possible to develop large area film fabrication methods. As the rough and hydrophobic surface properties of the flexible substrate, interfacial engineering will be conducted to modify the surface. Combining with the 2D perovskite, we will fabricate large perovskite thin film on the flexible substrate. Finally the efficient large flexible modules would be fabricated by the developed methods.

钙钛矿太阳能电池由于可以通过溶液法制备，成本低廉，吸引了众多的兴趣。其中尤其是柔性钙钛矿太阳能电池，有着可挠轻便等优点，更符合当前对光伏产品轻量化的需求。钙钛矿光伏走向产业化的障碍除了需要解决稳定性问题，还要实现大面积钙钛矿薄膜的制备。虽然目前报道了很多钙钛矿薄膜的制备方法，但是主要都是基于小面积薄膜的制备，并且很少探讨钙钛矿的成膜机制。钙钛矿材料在成膜过程中，其成核结晶机制到底是什么，是均质成核还是异质成核，受不受基底材料影响？这些关键性的基础问题仍然不清楚。本项目拟通过研究钙钛矿材料在大面积成膜过程中的成核结晶机制，揭示不同阳离子、不同卤素阴离子、不同基底材料对钙钛矿材料成核结晶行为的影响，从而为大面积钙钛矿成膜技术的开发提供理论支持 。此外，柔性衬底表面疏水，更难成膜，本项目将通过界面工程，修饰界面，改变界面性质，再结合二维钙钛矿掺杂技术，实现在柔性衬底的大面积钙钛矿薄膜及组件的制备。

钙钛矿太阳能电池作为一种新型光伏技术，具有低成本高效的特点，其应用光伏。其中，柔性钙钛矿太阳能电池轻薄可柔，可以用在可穿戴电子作为移动电源，应用前景广阔。但是柔性钙钛矿太阳能电池为了实现柔性，要在塑料基板上制备器件，由于塑料基板不耐受高温，必须开发低温薄膜制备技术。同时柔性基板更粗糙、更疏水，钙钛矿的成膜更难控制。为了制备高效柔性钙钛矿太阳能电池，我们首先研究柔性钙钛矿成核结晶机制，并通过组分、溶剂和添加剂进行调控，制备高质量大面积钙钛矿薄膜。再开发低温氧化锡电子传输层制备技术和稳定空穴传输层制备技术，结合飞秒激光加工技术，最终实现了10 cm x 10 cm柔性大面积钙钛矿太阳能电池组件的制备，效率超过13%。我们开发的低温印刷技术可以实现柔性钙钛矿太阳能电池组件的快速低能耗制备，极大地降低了柔性钙钛矿制备成本，也为未来柔性钙钛矿太阳能电池产业化提供了解决思路。