共轭有机小分子配体修饰实现高效高稳定太阳能电池(董化 Adv Func Mater 2019 DOI:10.1002/adfm.201808119)


2019-02-14

Conjugated Molecules “Bridge”: Functional Ligand toward Highly Efficient and Long-Term Stable Perovskite Solar Cell

 

Hua Dong, Jun Xi, Lijian Zuo, Jingrui Li, Yingguo Yang, Dongdong Wang, Yue Yu, Lin Ma, Chenxin Ran, Weiyin Gao, Bo Jiao, Jie Xu, Ting Lei, Feijie Wei, Fang Yuan, Lin Zhang, Yifei Shi, Xun Hou, and Zhaoxin Wu*

 

Interfacial ligand passivation engineering has recently been recognized as a promising avenue, contributing simultaneously to the optoelectronic characteristics and moisture/operation tolerance of perovskite solar cells. To further achieve a win-win situation of both performance and stability, an innovative conjugated aniline modifier (3-phenyl-2-propen-1-amine; PPEA) is explored to moderately tailor organolead halide perovskites films. Here, the conjugated PPEA presents both “quasi-coplanar” rigid geometrical configuration and distinct electron delocalization characteristics. After a moderate treatment, a stronger dipole capping layer can be formed at the perovskite/ transporting interface to achieve favorable banding alignment, thus enlarging the built-in potential and promoting charge extraction. Meanwhile, a conjugated cation coordinated to the surface of the perovskite grains/units can form preferably ordered overlapping, not only passivating the surface defects but also providing a fast path for charge exchange. Benefiting from this, a ≈21% efficiency of the PPEA-modified solar cell can be obtained, accompanied by long-term stability (maintaining 90.2% of initial power conversion efficiency after 1000 h testing, 25 °C, and 40 ± 10 humidity). This innovative conjugated molecule “bridge” can also perform on a larger scale, with a performance of 18.43% at an area of 1.96 cm2 .