Zhao Ruyan, Wang Wei, Liu Yamei, Petkov Petko, Khan Arafat Hossain, Gao Lei, Zhang Peng, Brunner Eike, Wang Hai I, Singh Shivam, Huang Shirong, Panes-Ruiz Luis Antonio, Vaynzof Yana, Bonn Mischa, Cuniberti Gianaurelio, Wang Mingchao, Feng Xinliang
Max Planck Institute of Microstructure Physics, Weinberg 2, Halle, 06120, Germany.
Faculty of Chemistry and Food Chemistry & Center for Advanced Electronics Dresden (cfaed), Technische Universität Dresden, Mommsenstraße 4, Dresden, 01062, Germany.
Angew Chem Int Ed Engl. 2025 Jun 10;64(24):e202504302. doi: 10.1002/anie.202504302. Epub 2025 May 2.
Two-dimensional (2D) conjugated polymers and their layer-stacked 2D conjugated covalent organic frameworks, such as 2D poly(arylene vinylene)s (2D PAVs), are emerging as promising polymer semiconductors for electronics and photocatalysis. However, achieving narrow optical band gaps and efficient electron transport remains a significant challenge for this class of materials to enhance the device's performance. Here, we report a donor-acceptor-type 2D PAV (2DPAV-TBDT-IT, where TBDT = thienyl-benzodithiophene and IT = s-indacene-1,3,5,7(2H,6H)-tetraone) synthesized via an Aldol-type 2D polycondensation approach. Notably, 2DPAV-TBDT-IT benefits from an effective intralayer donor-acceptor effect, exhibiting an optical band gap of 1.15 eV, the smallest among the reported 2D conjugated polymers. Density functional theory calculations reveal a unique electron-dominating transport for 2DPAV-TBDT-IT, with a strongly dispersive conduction band minimum and, thus, a small effective mass for electrons half that for holes. Additionally, terahertz spectroscopy measurements indicate a high charge mobility of 26 cm V s at room temperature for the powder sample. Given the high electron-deficiency of 2DPAV-TBDT-IT for facile electron injection from hazardous gases and the high-mobility electron-dominating transport in the material, we further fabricate chemiresistors from 2DPAV-TBDT-IT, showing ultrasensitive SO analyte detection with limit of detection of 0.088 ppb, significantly surpassing the reported chemiresistive SO sensors.
二维（2D）共轭聚合物及其层状堆叠的二维共轭共价有机框架，如二维聚（亚芳基乙烯撑）（2D PAVs），正成为用于电子学和光催化的有前途的聚合物半导体。然而，对于这类材料而言，实现窄光学带隙和高效电子传输仍然是提高器件性能的重大挑战。在此，我们报道了一种通过醛醇型二维缩聚方法合成的供体-受体型二维PAV（2DPAV-TBDT-IT，其中TBDT = 噻吩基-苯并二噻吩，IT = s-茚并-1,3,5,7(2H,6H)-四酮）。值得注意的是，2DPAV-TBDT-IT受益于有效的层内供体-受体效应，其光学带隙为1.15 eV，是已报道的二维共轭聚合物中最小的。密度泛函理论计算揭示了2DPAV-TBDT-IT独特的电子主导传输，其导带最小值具有强色散性，因此电子的有效质量较小，仅为空穴有效质量的一半。此外，太赫兹光谱测量表明，该粉末样品在室温下的电荷迁移率高达26 cm² V⁻¹ s⁻¹。鉴于2DPAV-TBDT-IT具有高电子缺陷性，便于从有害气体中进行电子注入，且材料中存在高迁移率的电子主导传输，我们进一步用2DPAV-TBDT-IT制备了化学电阻器，其对SO分析物的检测具有超灵敏性，检测限为0.088 ppb，显著超过了已报道的化学电阻式SO传感器。
