Chang Yun, Wu Ying-Sheng, Tung Shih-Huang, Chen Wen-Chang, Chueh Chu-Chen, Liu Cheng-Liang
Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan.
Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan.
ACS Appl Mater Interfaces. 2023 Mar 29;15(12):15745-15757. doi: 10.1021/acsami.2c23067. Epub 2023 Mar 15.
An integrated strategy of molecular design and conjugated polymer doping is proposed to improve the electronic characteristics for organic field effect transistor (OFET) applications. Here, a series of soluble naphthalene diimide ()-based random donor-acceptor copolymers with selenophene π-conjugated linkers and four acceptors with different electron-withdrawing strengths (named as ///) are synthesized, characterized, and used for OFETs. N-type doping of -based random copolymers using (12,18)-5,6,12,12,13,18,18,19-octahydro-5,6-dimethyl-13,18[1',2']-benzenobisbenzimidazo[1,2-:2',1'-]benzo[][2.5]benzodiazocine potassium triflate adduct () is successfully demonstrated. The undoped , , and samples exhibit ambipolar charge transport, while presents only a unipolar n-type characteristic. Doping with significantly modulates the performance of / OFETs, with a 3- to 6-fold increase in electron mobility (μ) for 1 wt % doped device due to simultaneous trap mitigation, lower contact resistance (), and activation energy (), and enhanced crystallinity and edge-on orientation for charge transport. However, the doping of intrinsic pro-quinoidal / films exhibits unchanged or even reduced device performance. These findings allow us to manipulate the energy levels by developing conjugated copolymers based on various acceptors and quinoids and to optimize the dopant-polymer semiconductor interactions and their impacts on the film morphology and molecular orientation for enhanced charge transport.
提出了一种分子设计与共轭聚合物掺杂相结合的策略，以改善有机场效应晶体管（OFET）应用中的电子特性。在此，合成、表征了一系列基于可溶性萘二亚胺（）的具有硒吩π共轭连接体的无规供体-受体共聚物以及四种具有不同吸电子强度的受体（命名为///），并将其用于OFET。成功展示了使用（12,18）-5,6,12,12,13,18,18,19-八氢-5,6-二甲基-13,18[1',2']-苯并双苯并咪唑[1,2-:2',1'-]苯并[][2.5]苯并二氮杂辛三氟甲磺酸钾加合物（）对基于的无规共聚物进行n型掺杂。未掺杂的、和样品表现出双极性电荷传输，而仅呈现单极性n型特性。用掺杂显著调节了/ OFET的性能，对于1 wt%掺杂的器件，电子迁移率（μ）提高了3至6倍，这归因于同时减轻陷阱、降低接触电阻（）和活化能（），以及增强了结晶度和电荷传输的边缘取向。然而，对本征前醌型/薄膜进行掺杂时，器件性能保持不变甚至降低。这些发现使我们能够通过开发基于各种受体和醌类的共轭共聚物来调控能级，并优化掺杂剂-聚合物半导体相互作用及其对薄膜形态和分子取向的影响，以增强电荷传输。
