Copper nanowires （CuNWs） are becoming an indispensable item for next- generation transparent optical devices due to their excellent conductivity and transparency. In this work, ultrathin semicircle-shaped copper nan...Copper nanowires （CuNWs） are becoming an indispensable item for next- generation transparent optical devices due to their excellent conductivity and transparency. In this work, ultrathin semicircle-shaped copper nanowires （SCuNWs） with a diameter of - 15 nm and a length of - 30 μm （aspect ratio of -2,000） were synthesized in ethanol solution. The mechanism and factors that affect the morphology and dispersity of the SCuNWs were investigated. The prepared SCuNWs were coated on polyethylene terephthalate （PET） or polyd- imethylsiloxane （PDMS） substrate to fabricate flexible transparent conductors （FTCs）. The fabricated FTCs exhibited excellent optoelectrical performance and low haze. In addition, the fabricated FTCs showed high mechanical stability during stretching and bending, indicating their great potential in flexible optical devices.展开更多
Microwave antennas are essential elements for various applications,such as telecommunication,radar,sensing,and wireless power transport.These antennas are conventionally manufactured on rigid substrates using opaque m...Microwave antennas are essential elements for various applications,such as telecommunication,radar,sensing,and wireless power transport.These antennas are conventionally manufactured on rigid substrates using opaque materials,such as metal strips,metallic tapes,or epoxy pastes;thus,prohibiting their use in flexible and wearable devices,and simultaneously limiting their integration into existing optoelectronic systems.Here,we demonstrate that mechanically flexible and optically transparent microwave antennas with high operational efficiencies can be readily fabricated using composite nanolayers deposited on common plastic substrates.The composite nanolayer structure consists of an ultra-thin copper-doped silver film sandwiched between two dielectric films of tantalum pentoxide and aluminum oxide.The material and thickness of each constituent layer are judiciously selected such that the whole structure exhibits an experimentally measured averaged visible transmittance as high as 98.94%compared to a bare plastic substrate,and simultaneously,a sheet resistance as low as 12.5Ω/sq.Four representative types of microwave antennas are implemented:an omnidirectional dipole antenna,unidirectional Yagi-Uda antenna,low-profile patch antenna,and Fabry-Pérot cavity antenna.These devices exhibit great mechanical flexibility with bending angle over 70°,high gain of up to 13.6 dBi,and large radiation efficiency of up to 84.5%.The proposed nano-engineered composites can be easily prepared over large areas on various types of substrates and simultaneously overcome the limitations of poor mechanical flexibility,low electrical conductivity,and reduced optical transparency usually faced by other constituent materials for flexible transparent microwave antennas.The demonstrated flexible microwave antennas have various applications ranging from fifth-generation and vehicular communication systems to bio-signal monitors and wearable electronics.展开更多
基金This work was supported by the National Natural Science Fund for Distinguished Young Scholars （No. 21425417）, the National Natural Science Foundation of China （Nos. 21603156 and 21704071）, Jiangsu Province Science Foundation for Youths （Nos. BK20170331 and BK20170332） and the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Copper nanowires （CuNWs） are becoming an indispensable item for next- generation transparent optical devices due to their excellent conductivity and transparency. In this work, ultrathin semicircle-shaped copper nanowires （SCuNWs） with a diameter of - 15 nm and a length of - 30 μm （aspect ratio of -2,000） were synthesized in ethanol solution. The mechanism and factors that affect the morphology and dispersity of the SCuNWs were investigated. The prepared SCuNWs were coated on polyethylene terephthalate （PET） or polyd- imethylsiloxane （PDMS） substrate to fabricate flexible transparent conductors （FTCs）. The fabricated FTCs exhibited excellent optoelectrical performance and low haze. In addition, the fabricated FTCs showed high mechanical stability during stretching and bending, indicating their great potential in flexible optical devices.
文摘Microwave antennas are essential elements for various applications,such as telecommunication,radar,sensing,and wireless power transport.These antennas are conventionally manufactured on rigid substrates using opaque materials,such as metal strips,metallic tapes,or epoxy pastes;thus,prohibiting their use in flexible and wearable devices,and simultaneously limiting their integration into existing optoelectronic systems.Here,we demonstrate that mechanically flexible and optically transparent microwave antennas with high operational efficiencies can be readily fabricated using composite nanolayers deposited on common plastic substrates.The composite nanolayer structure consists of an ultra-thin copper-doped silver film sandwiched between two dielectric films of tantalum pentoxide and aluminum oxide.The material and thickness of each constituent layer are judiciously selected such that the whole structure exhibits an experimentally measured averaged visible transmittance as high as 98.94%compared to a bare plastic substrate,and simultaneously,a sheet resistance as low as 12.5Ω/sq.Four representative types of microwave antennas are implemented:an omnidirectional dipole antenna,unidirectional Yagi-Uda antenna,low-profile patch antenna,and Fabry-Pérot cavity antenna.These devices exhibit great mechanical flexibility with bending angle over 70°,high gain of up to 13.6 dBi,and large radiation efficiency of up to 84.5%.The proposed nano-engineered composites can be easily prepared over large areas on various types of substrates and simultaneously overcome the limitations of poor mechanical flexibility,low electrical conductivity,and reduced optical transparency usually faced by other constituent materials for flexible transparent microwave antennas.The demonstrated flexible microwave antennas have various applications ranging from fifth-generation and vehicular communication systems to bio-signal monitors and wearable electronics.
