杂化钙钛矿的光伏效率已经达到22.1%，但要实用化必须解决重金属铅的替代问题。故本项目将围绕这一关键科学问题，设计与制备新型锡（II,IV）复合的非铅钙钛矿材料，实现高效的光伏器件。基于二价锡的钙钛矿材料合适的能隙及高载流子迁移率，但容易被氧化而不稳定，而四价锡钙钛矿材料化学稳定性好，但有空位缺陷，吸光能力稍弱，本项目结合二价锡与四价锡材料的优点，设计锡（II,IV）复合的新型非铅钙钛矿材料，如按照1:1的比例复合即得到A3Sn(IV)Sn(II)X9的非铅钙钛矿材料。主要1)通过有机阳离子的掺杂，改善四价锡钙钛矿材料的吸光能力及成膜性，如Csx(CH3NH3)2-xSnI6，(CH3NH3)2SnI6等；2)进一步通过二价锡掺杂四价锡钙钛矿，改善其吸光能力，设计锡（II,IV）复合的新型非铅钙钛矿光伏材料；3）研究锡（II,IV）复合型非铅钙钛矿材料的光伏性能，实现光伏效率突破15%。

Hybrid perovskite photovoltaic efficiency has reached 22.1%. For practical application, it has to be solved the problem of heavy metal lead substitution. Therefore, the project focus on this key scientific issues by designing and preparing new non-lead perovskite materials, in order to achieve efficient photovoltaic devices. In view of the suitable energy gap and high carrier mobility of the divalent tin perovskite material, it is easy to be oxidized and unstable, while the tetravalent tin perovskite material has good chemical stability, but there are vacancy defects. The combination of divalent tin and tetravalent tin materials are Sn(II, IV) composite of new non-lead perovskite materials, such as the ratio of 1: 1 A3Sn (IV) Sn (II) X9. The project: 1) with organic ions, new perovskite such as Csx(CH3NH3) 2-xSnI6, (CH3NH3) 2SnI6, etc . can be achieved with better film quality and absorption to sunlight; 2) through the divalent tin doping, to improve the absorption capacity of tetravalent tin perovskite materials and film-forming, such as Csx (CH3NH3) (II, IV) composite non-Pb perovskite materials; (3) to study the photovoltaic properties of Sn (II, IV) composite non-lead perovskite materials, and to study the photographic properties of tin (II, IV). The aim is to achieve a breakthrough in photovoltaic efficiency of 15%.