Both p-type conjugated polymers and n-type conjugated polymers are required for organic optoelectronic devices, such as organic solar cells (OSCs), organic field-effect transistors (OFETs), organic thermoelectrics (OTEs), etc. The development of n-type conjugated polymers lags far behind that of the p-type counterparts in view of material diversity and optoelectronic device performance. This is mainly due to the lack of strong electron-withdrawing building blocks, which are always based on the imide unit. Double boron–nitrogen coordination bond (B←N) bridged bipyridine (BNBP), which was first developed in 2016, is an alternative kind of electron-withdrawing building block based on a B←N unit. BNBP itself possesses a planar and fixed configuration, low-lying electronic energy levels, strong fluorescence, and facile functionalization. A family of BNBP-based conjugated polymers has been developed. They show excellent and tunable optoelectronic properties, such as high electron mobility, low-lying and tunable lowest unoccupied molecular orbital (LUMO) energy level (E_LUMO), medium bandgap, narrow absorption spectra in the visible range, high fluorescence quantum efficiency, etc. With rational molecular design of BNBP-based conjugated polymers, they have been widely used in organic optoelectronic devices with high performance, including OSCs, OFETs, and OTEs, indoor photovoltaics (IPVs), organic light-emitting diodes (OLEDs), organic photodetectors (OPDs), etc. Therefore, BNBP-based conjugated polymers have become an important class of optoelectronic materials. In this Account, we summarize the research progress on BNBP-based conjugated polymers.

中文翻译：

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基于双 B←N 桥联吡啶单元的 n 型共轭聚合物


有机光电器件需要 p 型共轭聚合物和 n 型共轭聚合物，例如有机太阳能电池 （OSC）、有机场效应晶体管 （OFET）、有机热电 （OTE） 等。n 型共轭聚合物的发展在材料多样性和光电器件性能方面远远落后于 p 型共轭聚合物。这主要是由于缺乏强吸电子构建块，这些构建块总是基于酰亚胺单元。双硼氮配位键 （B←N） 桥式联吡啶 （BNBP） 于 2016 年首次开发，是一种基于 B←N 单元的另一种吸电子构建单元。BNBP 本身具有平面和固定构型、低位电子能级、强荧光和简单的功能化。已经开发了一个基于 BNBP 的共轭聚合物系列。它们表现出优异且可调的光电特性，例如高电子迁移率、低位和可调的最低未占据分子轨道 （LUMO） 能级 （E_LUMO）、中等带隙、可见光范围内的窄吸收光谱、高荧光量子效率等。凭借基于 BNBP 的共轭聚合物的合理分子设计，它们已广泛应用于高性能的有机光电器件中，包括 OSC、OFET 和 OTE、室内光伏 （IPVs）、有机发光二极管 （OLED）、有机光电探测器 （OPD） 等。因此，基于 BNBP 的共轭聚合物已成为一类重要的光电材料。在本账户中，我们总结了基于 BNBP 的共轭聚合物的研究进展。