Yang Song, Yu Bo, Yu Huangzhong
School of Physics and Optoelectronics, South China University of Technology, Guangzhou, 510640, China.
Small Methods. 2025 Apr;9(4):e2401307. doi: 10.1002/smtd.202401307. Epub 2024 Oct 14.
Molecular doping of organic semiconductor is a great strategy for significantly regulating the electronic band structure of organic semiconductor while increasing charge mobility and carrier concentration. Here, a facile strategy is presented by introducing 2D g-CN as a p-dopant into PM6, improving the charge mobility and hole carrier concentration of PM6. Moreover, the electron transfer between PM6 and g-CN can effectively downshift the Fermi energy level and highest occupied molecular orbital (HOMO) energy level of PM6, which leads to the increase the built-in electric field of organic solar cells (OSCs). The addition of g-CN also effectively enhances the crystallization of active layer, thereby improving the stability of OSCs. As a result, a champion bulk-heterojunction (BHJ) and layer-by-layer (LbL) structure OSCs are successfully achieved featuring a high-power conversion efficiency of 18.10%/18.25%, simultaneously having excellent device stability. This work shows that introducing a low concentration dopant into organic donor is an effective method for improving the electrical performance of organic donor and the efficiency of OSCs.
有机半导体的分子掺杂是一种显著调节有机半导体电子能带结构、同时提高电荷迁移率和载流子浓度的有效策略。在此，我们提出了一种简便的策略，即将二维石墨相氮化碳（g-CN）作为p型掺杂剂引入到PM6中，提高了PM6的电荷迁移率和空穴载流子浓度。此外，PM6与g-CN之间的电子转移能够有效地降低PM6的费米能级和最高占据分子轨道（HOMO）能级，从而增加有机太阳能电池（OSC）的内建电场。g-CN的添加还有效地增强了活性层的结晶度，进而提高了OSC的稳定性。结果，成功制备出了具有18.10%/18.25%的高功率转换效率、同时具有优异器件稳定性的冠军体相异质结（BHJ）和逐层（LbL）结构的OSC。这项工作表明，向有机供体中引入低浓度掺杂剂是提高有机供体电学性能和OSC效率的有效方法。
