Dong Hao, Zheng Erjin, Niu Zhiyin, Zhang Xiaoyu, Lin Yi-Yu, Jain Priyesh, Yu Qiuming
Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States.
ACS Appl Mater Interfaces. 2020 Apr 15;12(15):17571-17582. doi: 10.1021/acsami.0c01756. Epub 2020 Apr 1.
Poly(hydroxymethylated-3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT-MeOH:PSS) conducting polymers are synthesized and incorporated in inverted structured perovskite solar cells (PVSCs) as hole transport materials. The highest occupied molecular orbital of PEDOT-MeOH is lowered by adding a hydroxymethyl (-MeOH) functional group to ethylenedioxythiophene (EDOT), and thus, the work function of PEDOT-MeOH:PSS is increased. Additionally, hydrogen bonding can be formed among EDOT-MeOH monomers and between EDOT-MeOH monomers and sulfate groups on PSS, which promotes PEDOT-MeOH chain growth and enhances PSS doping. The electronic, microstructural, and surface morphological properties of PEDOT-MeOH:PSS are modified by changing the amounts of PSS and the ferric oxidizing agent used in the polymerization and by adding ethylene glycol in the postsynthesis treatment. The PVSCs based on ethylene-glycol-treated PEDOT-MeOH:PSS overperform the PVSCs based on commercial PEDOT:PSS because of the better energetic alignment and the enhancement of PEDOT-MeOH:PSS electrical conductivity. This work opens the way to develop new hole transport materials for highly efficient inverted PVSCs.
聚（羟甲基化-3,4-乙撑二氧噻吩）：聚苯乙烯磺酸盐（PEDOT-MeOH:PSS）导电聚合物被合成并作为空穴传输材料掺入倒置结构的钙钛矿太阳能电池（PVSCs）中。通过向乙撑二氧噻吩（EDOT）添加羟甲基（-MeOH）官能团，PEDOT-MeOH的最高占据分子轨道降低，因此，PEDOT-MeOH:PSS的功函数增加。此外，EDOT-MeOH单体之间以及EDOT-MeOH单体与PSS上的硫酸根之间可以形成氢键，这促进了PEDOT-MeOH链的生长并增强了PSS掺杂。通过改变聚合中使用的PSS和铁氧化剂的量以及在合成后处理中添加乙二醇，对PEDOT-MeOH:PSS的电子、微观结构和表面形态性质进行了改性。基于乙二醇处理的PEDOT-MeOH:PSS的PVSCs由于更好的能量匹配和PEDOT-MeOH:PSS电导率的提高，性能优于基于商业PEDOT:PSS的PVSCs。这项工作为开发用于高效倒置PVSCs的新型空穴传输材料开辟了道路。
