用于钙钛矿/体异质结集成太阳电池的新型电子传输层材料

The perovskite solar cells, which hold a latest certified PCE more than 20 %, have developed exceedingly in the past six years. It is of great potential in commercial applications. The integrated solar cells, which prepared by implanting the BHJ layer in perovskite solar cells, hold remarkably broader light response. This may increase the photocurrent and the efficiency of the solar cells. This project plans to develop novel fullerene electron transport layers (ETL) to optimize the interface contact of the integrated solar cells, increase the photocurrent and further improve the performance. 1. We plan to design and develop the "bi-functional groups” fullerene derivatives. On one hand the material holds an anchor group, which will have a higher affinity to the titania through covalent bond. On the other hand, the fullerene has an ammonium salt or thiophene group, which may improve the crystalline morphology of the perovskite layer. 2. We plan to design and develop the alcohol-soluble fullerene derivatives, which will be used to improve the electron transport and collection between the BHJ layer and metal electrode. Meantime, it will avoid the use of Ca and improve the stability of the devices. These two issues are interested in further increasing the electron transport and improving the photocurrent by the novel fullerene derivatives, thereby enhance the performance and stability of the devices. It will establish important foundation for the commercial application of the integrated solar cells.

6年来，钙钛矿太阳电池发展迅猛，能量转化效率突破20%，具有巨大商业应用潜力。将体异质结植入钙钛矿电池制备集成太阳电池可以显著拓宽光响应，提高光电流和电池效率。为了改善钙钛矿/体异质结集成电池界面电子传输，本项目拟采用富勒烯电子传输层，优化界面接触，提高光电流，进一步提高集成电池效率，研究方案：1.设计开发双官能团富勒烯电子传输材料，用于钙钛矿/二氧化钛界面。此类材料一方面具有亲二氧化钛锚定基团，可直接固定在二氧化钛表面；另一方面具有铵盐或者噻吩结构，能有效改善界面钙钛矿结晶。2.设计开发醇溶性富勒烯衍生物，改善体异质结/金属界面电子传输和收集，置换金属钙以提高电池稳定性。采用上述高性能富勒烯电子传输层改善电池界面接触，有效促进电子传输，提高集成电池光电流，可以大幅提高电池效率和稳定性，为集成太阳电池商业应用奠定重要基础。

在国家自然科学基金（51503050）的资助下，围绕应用于钙钛矿/体异质结集成电池的多种双官能团富勒烯，醇溶性富勒烯界面材料的合成开展了研究，同时在钙钛矿空穴传输层界面修饰、新型无铅钙钛矿电池以及新型体异质结给体材料方面开展了研究，具体如下：.1. 开展了双官能团富勒烯衍生物以及醇溶性界面材料的设计合成，初步探索了其在钙钛矿太阳电池中的应用。.2. 开展了钙钛矿空穴传输材料PEDOT:PSS的修饰研究，将PSS-Na掺到PEDOT:PSS中，提高了PEDOT:PSS的透过率和功函数，实现了钙钛矿电池效率的显著明显，同时将其应用到CH3NH3PbBr3钙钛矿体系中，实现了1.52 V的Voc。.3. 开展了新型无铅钙钛矿材料的研究，制备了基于(NH4)3Sb2I9的电池器件，实现了1.03 V的Voc，并成功生长了单晶。.4. 设计合成了一种新型宽带隙高分子给体材料PBD2T，在非富勒烯电池中实现10.34%的效率。