Hurtado-Gallego Juan, Sangtarash Sara, Davidson Ross, Rincón-García Laura, Daaoub Abdalghani, Rubio-Bollinger Gabino, Lambert Colin J, Oganesyan Vasily S, Bryce Martin R, Agraït Nicolás, Sadeghi Hatef
Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
Device Modelling Group, School of Engineering, University of Warwick, CV4 7AL Coventry, United Kingdom.
Nano Lett. 2022 Feb 9;22(3):948-953. doi: 10.1021/acs.nanolett.1c03698. Epub 2022 Jan 24.
Organic thermoelectric materials have potential for wearable heating, cooling, and energy generation devices at room temperature. For this to be technologically viable, high-conductance () and high-Seebeck-coefficient () materials are needed. For most semiconductors, the increase in is accompanied by a decrease in . Here, using a combined experimental and theoretical investigation, we demonstrate that a simultaneous enhancement of and can be achieved in single organic radical molecules, thanks to their intrinsic spin state. A counterintuitive quantum interference (QI) effect is also observed in stable Blatter radical molecules, where constructive QI occurs for a -connected radical, leading to further enhancement of thermoelectric properties. Compared to an analogous closed-shell molecule, the power factor is enhanced by more than 1 order of magnitude in radicals. These results open a new avenue for the development of organic thermoelectric materials operating at room temperature.
有机热电材料在室温下具有用于可穿戴加热、冷却和能量产生装置的潜力。要使其在技术上可行，需要高电导率（）和高塞贝克系数（）的材料。对于大多数半导体而言，电导率的增加伴随着塞贝克系数的降低。在此，通过结合实验和理论研究，我们证明由于其固有的自旋态，在单个有机自由基分子中可以同时提高电导率和塞贝克系数。在稳定的布拉特自由基分子中还观察到一种违反直觉的量子干涉（QI）效应，其中对于-连接的自由基发生相长性QI，导致热电性能的进一步增强。与类似的闭壳分子相比，自由基中的功率因数提高了1个多数量级。这些结果为开发在室温下工作的有机热电材料开辟了一条新途径。
