N-Type Self-Doped Hyperbranched Conjugated Polyelectrolyte as Electron Transport Layer for Efficient Nonfullerene Organic Solar Cells
N-Type Self-Doped Hyperbranched Conjugated Polyelectrolyte as Electron Transport Layer for Efficient Nonfullerene Organic Solar Cells
复制标题
N型自掺杂超支化共轭聚电解质作为高效非富勒烯有机太阳能电池的电子传输层
DOI：
10.1021/acsami.1c13394
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发表时间：
2021
影响因子：
9.5
通讯作者：
Lie Chen
中科院分区：
文献类型：
--
作者：
Dan Zhou;Wen You;Fei Yang;Rui Chen;Haitao Xu;Yongfen Tong;Bin Hu;Lin Hu;Yu Xie;Lie Chen
电子传输层（ETL）对非富勒烯有机太阳能电池（NOSC）的功率转换效率（PCE）产生巨大影响。目前，大多数有机ETL的导电性较差，不利于载流子的传输和收集。在此，我们设计并开发了一种基于n型苝二酰亚胺（PDI）作为中心核和季铵盐作为侧极性基团的新型超支化共轭聚电解质（CPE）。氮原子的孤对电子可以转移到缺电子的PDI核，赋予分子高效的n型自掺杂效应。此外，超支化结构使分子具有更多的侧极性基团，有利于形成更多的偶极子和更强的偶极矩。因此，CPE PTPAPDINO具有高电导率，可以显着降低电极的功函数（WF），有助于器件的载流子传输和收集。采用 PTPAPDINO 作为 ETL 的 NOSC 提供了 15.62% 的出色 PCE，甚至优于使用经典 PDINO ETL 的设备。此外，当厚度增加到28 nm时，PCE可以保留最佳器件的82.6%。这些结果表明，设计n型自掺杂超支化CPE作为高效ETL是一种可行的策略，并且PTPAPDINO是高性能NOSCs的一种有前途的替代ETL。
The electron transport layer (ETL) exerts a dramatic influence on the power conversion efficiency (PCE) of the nonfullerene organic solar cells (NOSCs). Currently, the majority of the organic ETLs possess a relatively poor conductivity, which is not conducive to carrier transport and collection. Herein, we design and develop a novel hyperbranched conjugated polyelectrolyte (CPE) based on n-type perylene diimide (PDI) as the center core and quaternary ammonium salt as the side polar groups. The lone pair electrons of the nitrogen atoms can transfer to the electron deficient PDI core and endow the molecule with an efficient n-type self-doping effect. Moreover, the hyperbranched structure makes the molecule functionalized with more side polar groups, favoring forming more dipoles and stronger dipole moments. Therefore, the CPE PTPAPDINO possesses a high conductivity and can notably decrease the work function (WF) of the electrode, contributing to the carrier transport and collection of the device. The NOSC with PTPAPDINO as ETL delivers an excellent PCE of 15.62%, which is even superior to the device using the classical PDINO ETL. Moreover, the PCE can retain 82.6% of the optimal device when the thickness has been increased to 28 nm. These results manifest that it is a feasible strategy to design an n-type self-doping hyperbranched CPE as efficient ETL, and PTPAPDINO is a promising alternative ETL for high performance NOSCs.