Thanks to its high electrical conductivity, a graphene plane presents a good shielding efficiency against GHz electromagnetic radiations. Several graphene planes separated by thin polymer spacers add their conductivities arithmetically, because each of them conserves the intrinsic properties of isolated graphene. Maximum absorption of radiations for frequency around 30 GHz is achieved with six separated graphene planes, which is the optimum number. This remarkable result is demonstrated experimentally from electromagnetic measurements performed in the Ka band on a series of multilayers obtained by piling 1, 2, 3... graphene/PMMA units on a silica substrate. Theoretical calculations convincingly explain the observed absorption and transmission data in the GHz domain. It is concluded that graphene/PMMA multilayers can be used as an efficient optically transparent and flexible shielding media.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4244631 | PMC |
http://dx.doi.org/10.1038/srep07191 | DOI Listing |
ACS Nano
January 2025
Department of Chemical and Biomolecular Engineering, Lehigh University, 124 E. Morton Street, Bethlehem, Pennsylvania 18015, United States.
Quantum dot (QD) light-emitting diodes (QLEDs) are promising candidates for next-generation displays because of their high efficiency, brightness, broad color gamut, and solution-processability. Large-scale solution-processing of electroluminescent QLEDs poses significant challenges, particularly concerning the precise control of the active layer's thickness and uniformity. These obstacles directly impact charge transport, leading to current leakage and reduced overall efficiency.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou, 434023, P.R. China.
Metamaterials hold great promise for application in the field of perfect absorbers due to their remarkable ability to manipulate electromagnetic waves. In this work, a full-spectrum ultra-wideband solar absorber with a multilayer metal-dielectric stacked structure is designed. Our absorber is simple and easy to manufacture, with Ti serving as the substrate, overlaid with SiN spacer layers and four pairs of Ti-SiN ring columns.
View Article and Find Full Text PDFInspired by human skin, bionic tactile sensing is effectively promoting development and innovation in many fields with its flexible and efficient perception capabilities. Optical fiber, with its ability to perceive and transmit information and its flexible characteristics, is considered a promising solution in the field of tactile bionics. In this work, one optical fiber tactile sensing system based on a flexible PDMS-embedded optical fiber ring resonator (FRR) is designed for braille recognition, and the Pound-Drever-Hall (PDH) demodulation scheme is adopted to improve the detection sensitivity.
View Article and Find Full Text PDFThe time-resolved backlight imaging of plasma is crucial for diagnosing density-dependent plasma information. It requires a high-intensity X-ray source and efficient optics. We propose a quasi-coaxial, multi-channel Kirkpatrick-Baez (KB) structure that realizes high-brightness illumination.
View Article and Find Full Text PDFBeyond 5 G and 6 G, communication systems should be able to deliver high throughput, low latency, high dependability, and high energy efficiency services. The creation of hybrid systems that can meet and largely satisfy these needs is promised by the merging of systems based on optical communication and radio frequency (RF). Smart devices may work together to cooperatively train Machine Learning (ML) models in a distributed fashion using Federated Learning (FL), all without disclosing personal information to a central server.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!