“马鞍型”钙钛矿太阳能电池空穴传输材料合成及性能

Perovskite Solar cells (PSCs) is one of the most promising novel solar cells, and the hole transporting materials (HTMs) play key roles in PSCs. In this project, several new hole transporting materials based on cyclooctatetrathiophenes (COThs) will be designed and synthesized, the new materials consist of a “Saddle-shaped” core and four side chains of oligothiophenes. Herein, two strategies will be carried out to develop novel and high efficient HTMs. One is tuning the molecular high occupied molecular orbital (HOMO)/low unoccupied molecular orbital (LUMO) energy by introducing the side chains such as Me, Et, or more bulky substitutes at 3-position of thiophene units, which will make the HTMs' HOMO energy match better with that of Pervoskite and enhance the solar cells efficiency; the other one is suppressing charge recombination and enhancing charge dissociation on the interface between HTMs and Perovskite by introducing the “Saddle-shaped” core structure of COTh to improve power conversion efficiency (PCE) of PSCs. The relationship between THMs’structure and their HOMO/LUMO energies will be derived from the first strategy and that between charge recombination/dissociation and the HTMs’ sturctures from the further optimization of THMs' structures, which will provide a guidance for developing high efficient and stable PSCs in future.

钙钛矿太阳能电池是近年来发展迅速、效率提升最快的新型太阳能电池之一。空穴传输材料是钙钛矿太阳能电池的重要组成部分。本项目针对目前钙钛矿太阳能电池中空穴传输材料迁移率低，需要金属离子盐等对其进行掺杂和材料HOMO能级与钙钛矿材料不匹配的难题，拟设计合成几种以“马鞍型”结构的环辛四噻吩（COTh）骨架为核，寡聚噻吩及其衍生物为边臂的新型空穴传输材料。通过研究材料分子结构对其HOMO/LUMO能级及载流子传输性能的影响规律，调节材料分子HOMO能级使之与钙钛矿材料相匹配；通过研究刚性、扭曲蓬松的“马鞍型”骨架对电池中空穴传输层与钙钛矿层界面处的电荷复合影响规律，最终获得几种新型、高效、高疏水性的钙钛矿太阳能电池空穴传输层材料，为进一步提升钙钛矿太阳能电池效率和稳定性提供新的研究思路。

钙钛矿太阳能电池是近年来发展迅速、效率提升最快的新型太阳能电池之一。空穴传输材料是钙钛矿太阳能电池的重要组成部分，对器件效率和稳定性具有重要影响。本项目针对目前钙钛矿太阳能电池中空穴传输材料迁移率低，需要金属离子盐等对其进行掺杂和材料HOMO能级与钙钛矿材料不匹配的难题，合成了几种基于环辛四噻吩（COTh）骨架这一“马鞍型”结构的新型空穴传输材料。通过研究材料分子结构对其HOMO/LUMO能级及载流子传输性能的影响规律，调节材料分子HOMO能级使之与钙钛矿材料相匹配；通过研究刚性、扭曲蓬松的“马鞍型”骨架对电池中空穴传输层与钙钛矿层界面处的电荷复合影响规律，最终获得四类新型、高效、高疏水性的钙钛矿太阳能电池空穴传输层材料，实现了最高电池效率大于20%，在20%湿度空气中保持1000小时的高稳定性钙钛矿太阳能电池，为进一步提升钙钛矿太阳能电池效率和稳定性积累了宝贵经验，为进一步优化材料设计奠定了基础。