The coupling of an electromagnetic plane wave to a thin conductor depends on the sheet conductance of the material: a poor conductor interacts weakly with the incoming light, allowing the majority of the radiation to pass; a good conductor also does not absorb, reflecting the wave almost entirely. For suspended films, the transition from transmitter to reflector occurs when the sheet resistance is approximately the characteristic impedance of free space (Z = 377 Ω). Near this point, the interaction is maximized, and the conductor absorbs strongly. Here we show that monolayer graphene, a tunable conductor, can be electrically modified to reach this transition, thereby achieving the maximum absorptive coupling across a broad range of frequencies in terahertz (THz) band. This property to be transparent or absorbing of an electromagnetic wave based on tunable electronic properties (rather than geometric structure) is expected to have numerous applications in mm wave and THz components and systems.
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http://dx.doi.org/10.1038/s41467-017-02336-z | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Materials and Energy, Lanzhou University (LZU), Lanzhou 730000, China.
Complementary neural network circuits combining multifunctional high-performance p-type with n-type organic artificial synapses satisfy sophisticated applications such as image cognition and prosthesis control. However, implementing the dual-modal memory features that are both volatile and nonvolatile in a synaptic transistor is challenging. Herein, for the first time, we propose a single vertical n-type organic synaptic transistor (VNOST) with a novel polymeric organic mixed ionic-electronic conductor as the core channel material to achieve dual-modal synaptic learning/memory behaviors at different operating current densities via the formation of an electric double layer and the reversible ion doping.
View Article and Find Full Text PDFNat Nanotechnol
January 2025
Department of Physics and Astronomy, University of California, Irvine, CA, USA.
Spin-orbit torques enable energy-efficient manipulation of magnetization by electric current and hold promise for applications ranging from non-volatile memory to neuromorphic computing. Here we report the discovery of a giant spin-orbit torque induced by anomalous Hall current in ferromagnetic conductors. This anomalous Hall torque is self-generated as it acts on the magnetization of the ferromagnet that engenders the torque.
View Article and Find Full Text PDFNature
January 2025
Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, School of Materials Science and Engineering, Peking University, Beijing, China.
With promises for high specific energy, high safety and low cost, the all-solid-state lithium-sulfur battery (ASSLSB) is ideal for next-generation energy storage. However, the poor rate performance and short cycle life caused by the sluggish solid-solid sulfur redox reaction (SSSRR) at the three-phase boundaries remain to be solved. Here we demonstrate a fast SSSRR enabled by lithium thioborophosphate iodide (LBPSI) glass-phase solid electrolytes (GSEs).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Proton-electron mixed conductors (PEMCs) are an essential component for potential applications in hydrogen separation and energy conversion devices. However, the exploration of PEMCs with excellent mixed conduction, which is quantified by the ambipolar conductivity, σ = σσ/(σ + σ) (σ: electronic conductivity; σ: proton conductivity), is still a great challenge, largely due to the lack of structural characterization of both conducting mechanisms. In this study, we prepared a molecule-based proton-electron mixed-conducting cation radical salt, (ET)[Pt(pop)(Hpop)]·PhCN (ET: bis(ethylenedithio)tetrathiafulvalene, pop: PHO), by electrocrystallization.
View Article and Find Full Text PDFAdv Mater
January 2025
Department of Nano Engineering, Department of Nano Science and Technology, Sungkyunkwan University Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Seobu-ro 2066, Jangan-gu, Suwon, 16419, Republic of Korea.
Carbon nanotubes (CNTs) produced by the floating-catalyst chemical vapor deposition (FCCVD) method are among the most promising nanomaterials of today, attracting interest from both academic and industrial sectors. These CNTs exhibit exceptional electrical conductivity, optical properties, and mechanical resilience due to their binder-free and low-defect structure, while the FCCVD method enables their continuous and scalable synthesis. Among the methodological FCCVD variations, aerosol CVD' is distinguished by its production of freestanding thin films comprising macroscale CNT networks, which exhibit superior performance and practical applicability.
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