Kuang Chaoyang, Chen Shangzhi, Luo Min, Zhang Qilun, Sun Xiao, Han Shaobo, Wang Qingqing, Stanishev Vallery, Darakchieva Vanya, Crispin Reverant, Fahlman Mats, Zhao Dan, Wen Qiye, Jonsson Magnus P
Laboratory of Organic Electronics, Department of Science and Technology (ITN), Linköping University, Norrköping, SE-601 74, Sweden.
School of Electronic Science and Engineering, State Key Laboratory of Electronic Thin Film and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610 054, P. R. China.
Adv Sci (Weinh). 2024 Jan;11(3):e2305898. doi: 10.1002/advs.202305898. Epub 2023 Nov 23.
Terahertz (THz) technologies provide opportunities ranging from calibration targets for satellites and telescopes to communication devices and biomedical imaging systems. A main component will be broadband THz absorbers with switchability. However, optically switchable materials in THz are scarce and their modulation is mostly available at narrow bandwidths. Realizing materials with large and broadband modulation in absorption or transmission forms a critical challenge. This study demonstrates that conducting polymer-cellulose aerogels can provide modulation of broadband THz light with large modulation range from ≈ 13% to 91% absolute transmission, while maintaining specular reflection loss < -30 dB. The exceptional THz modulation is associated with the anomalous optical conductivity peak of conducting polymers, which enhances the absorption in its oxidized state. The study also demonstrates the possibility to reduce the surface hydrophilicity by simple chemical modifications, and shows that broadband absorption of the aerogels at optical frequencies enables de-frosting by solar-induced heating. These low-cost, aqueous solution-processable, sustainable, and bio-friendly aerogels may find use in next-generation intelligent THz devices.
太赫兹（THz）技术提供了从卫星和望远镜的校准目标到通信设备和生物医学成像系统等一系列机会。一个主要组件将是具有可切换性的宽带太赫兹吸收器。然而，太赫兹波段的光学可切换材料稀缺，并且它们的调制大多在窄带宽下可用。实现具有大的宽带吸收或透射调制的材料构成了一项关键挑战。本研究表明，导电聚合物 - 纤维素气凝胶能够实现对宽带太赫兹光的调制，其绝对透射率的调制范围从约13%到91%，同时保持镜面反射损耗＜ -30 dB。这种优异的太赫兹调制与导电聚合物的反常光导率峰值相关，该峰值在其氧化状态下增强了吸收。该研究还证明了通过简单的化学修饰降低表面亲水性的可能性，并表明气凝胶在光频下的宽带吸收能够通过太阳能诱导加热实现除霜。这些低成本、可通过水溶液加工、可持续且对生物友好的气凝胶可能会应用于下一代智能太赫兹设备。
