Sn基钙钛矿晶体薄膜及其室内光伏特性

Compared with lead-based perovskites, tin (Sn)-based perovskites exhibit not only similar or even superior electronic and optical properties, including narrower optical band gaps, smaller exciton binding energies and higher mobility. Moreover, Sn is an environmentally friendly element and is more preferred candidate for application in the perovskite solar cells as replacement for toxic lead in perovskite solar cells. In this project, a solution process exploited for the preparation of a stable and high quality Sn-based perovskite film. The aim of this project is to investigate the effect of high quality and stable crystal characteristics of Sn-based perovskite for indoor photovoltaic application. First，based on the quality and stability of Sn-based perovskite film crystals to improve the performance of Sn-based perovskite devices, the effects of different crystallization methods on the crystal quality of the film and the stability of the reducing additive on the stability of the film will be systematically investigated. Second, the relationship between the microstructure of the Sn-based perovskite and the photoelectric properties of the film will be investigated with synchrotron radiation facility and several characterization techniques will be employed to understand the mechanism of formation of photo-generated carriers, the transport process of electrons and holes in Sn-based perovskites under indoor lighting. The project provides a novel route for high-efficiency and stable non-lead perovskite solar cells in the indoor applications of low-power wireless electronic devices, IOT (IOT-internet of things). Making understanding from fundamental and advanced characterization of Sn-based perovskite. The project will be directed to fine-tune the desired composition and characteristics of Sn-based material to develop high-performance perovskite solar cells approaching indoor photoelectric conversion efficiency of more than 20%. The project provides a novel route for high-efficiency and stable non-lead perovskite solar cells in the indoor applications of low-power wireless electronic devices.

锡（Sn）基钙钛矿与铅基钙钛矿相比，不仅具有相似甚至更优越的电学和光学特性，例如更窄的光学带隙、较小的激子结合能和更高的载流子迁移率，而且Sn是一种环境友好型元素，更有利于钙钛矿光伏电池的绿色化商业应用。本项目拟从Sn基钙钛矿的晶体生长出发，探索采用溶液法制备高质量Sn基钙钛矿晶体薄膜的新方法，并研究该晶体薄膜的质量及稳定性对其器件性能、尤其是对其室内光伏特性的影响。首先，研究不同结晶方法对薄膜结晶质量的影响，研究还原型添加剂对其稳定性的影响，并进一步通过同步辐射原位装置揭示Sn基钙钛矿微结构与其薄膜光电性能的联系。其次，在理解Sn基钙钛矿室内弱光条件下光生载流子的产生机理、输运过程以及缺陷机制的基础上，研制出室内光电转换效率超过20%的Sn基钙钛矿光伏电池，从而为高效率、高稳定性的无毒钙钛矿光伏电池在室内低功耗电子设备上的应用，提供更多的技术思路和理论依据。

锡（Sn）基钙钛矿作为钙钛矿光伏电池绿色化商业应用的潜在候选者，具有广阔的发展前景。然而，Sn基钙钛矿快速且无序结晶以及表面Sn2+易于氧化为Sn4+，限制其进一步发展。鉴于此，本项目主要从Sn基钙钛矿的晶体生长出发，探索采用溶液法制备高质量Sn基钙钛矿晶体薄膜的新方法，并研究该晶体薄膜的质量及稳定性对其器件性能的影响。首先，研究不同结晶方法对薄膜结晶质量的影响如在FASnI3的退火过程中引入氯化苯乙铵（PEACl），能够形成垂直定向的更有序的2D锡基钙钛矿晶体，并通过同步辐射原位装置揭示Sn基钙钛矿微结构与其薄膜光电性能的联系。其次，研究还原型添加剂对其稳定性的影响，如在钙钛矿前驱体溶液中引入离子液体乙酸丁铵 (BAAc)，BAAc与SnI2之间通过形成O...Sn 螯合键和N-H...X 氢键能够有效遏制DMSO对Sn (II) 的氧化，这些键合作用也能进一步调节钙钛矿薄膜的结晶过程，提供更多均一的成核位点，使得制备的薄膜更加致密且具有优先的晶体取向，提升器件稳定性，同时实现了超过10%的能量转换效率。再次，通过研究引入PDINO改善钙钛矿薄膜晶体，同时深入理解钙钛矿室内弱光条件下光生载流子的产生机理、输运过程以及缺陷机制，实现了37.9%室内能量转换效率，为深入研究Sn基钙钛矿室内光伏奠定基础。最后，就Sn基钙钛矿发展和挑战，Sn基钙钛矿稳定性提升策略以及室内光伏的应用与挑战等做了综述研究。本项目的完成为高效率、高稳定性的无毒钙钛矿光伏电池在室内低功耗电子设备上的应用，提供更多的技术思路和理论依据。