Ren Ming, Fang Lingyi, Zhang Yuyan, Eickemeyer Felix T, Yuan Yi, Zakeeruddin Shaik M, Grätzel Michael, Wang Peng
State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Chemistry, Zhejiang University, Hangzhou, 310058, China.
Laboratory of Photonics and Interfaces, Institute of Chemical Science and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, CH 1015, Switzerland.
Adv Mater. 2024 Jul;36(27):e2403403. doi: 10.1002/adma.202403403. Epub 2024 Apr 23.
Efficient and robust n-i-p perovskite solar cells necessitate superior organic hole-transport materials with both mechanical and electronic prowess. Deciphering the structure-property relationship of these materials is crucial for practical perovskite solar cell applications. Through direct arylation, two high glass transition temperature molecular semiconductors, DBC-ETPA (202 °C) and TPE-ETPA (180 °C) are synthesized, using dibenzo[g,p]chrysene (DBC) and 1,1,2,2-tetraphenylethene (TPE) tetrabromides with triphenylene-ethylenedioxythiophene-dimethoxytriphenylamine (ETPA). In comparison to spiro-OMeTAD, both semiconductors exhibit shallower HOMO energy levels, resulting in increased hole densities (generated by air oxidation doping) and accelerated hole extraction from photoexcited perovskite. Experimental and theoretical studies highlight the more rigid DBC core, enhancing hole mobility due to reduced reorganization energy and lower energy disorder. Importantly, DBC-ETPA possesses a higher cohesive energy density, leading to lower ion diffusion coefficients and higher Young's moduli. Leveraging these attributes, DBC-ETPA is employed as the primary hole-transport layer component, yielding perovskite solar cells with an average efficiency of 24.5%, surpassing spiro-OMeTAD reference cells (24.0%). Furthermore, DBC-ETPA-based cells exhibit superior operational stability and 85 °C thermal storage stability.
高效且稳健的n-i-p钙钛矿太阳能电池需要具有机械和电子性能的优质有机空穴传输材料。解读这些材料的结构-性能关系对于实际的钙钛矿太阳能电池应用至关重要。通过直接芳基化反应，使用二苯并[g,p]萘（DBC）和1,1,2,2-四苯基乙烯（TPE）四溴化物与三亚苯基-乙二氧基噻吩-二甲氧基三苯胺（ETPA）合成了两种高玻璃化转变温度的分子半导体，即DBC-ETPA（202℃）和TPE-ETPA（180℃）。与螺环-OMeTAD相比，这两种半导体均表现出较浅的HOMO能级，从而导致空穴密度增加（由空气氧化掺杂产生）并加速从光激发钙钛矿中提取空穴。实验和理论研究表明，更刚性的DBC核心由于重组能降低和能量无序性降低而提高了空穴迁移率。重要的是，DBC-ETPA具有更高的内聚能密度，导致更低的离子扩散系数和更高的杨氏模量。利用这些特性，DBC-ETPA被用作主要的空穴传输层组件，得到的钙钛矿太阳能电池平均效率为24.5%，超过了螺环-OMeTAD参考电池（24.0%）。此外，基于DBC-ETPA的电池表现出优异的运行稳定性和85℃的热存储稳定性。
