As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorptio...As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorption bandwidth while ensuring high absorption efficiency. In this work, we proposed a hybrid nanostructure, which not only can improve absorption efficiency but also can increase absorption bandwidth. The proposed hybrid nanostructure consists of a monolayer graphene sandwiched between three Ag gratings with different widths and a SiO2 spacer on a Ag substrate, these three gratings and substrate can excite three independent magnetic dipole resonances. In our calculations, we numerically demonstrate the proposed hybrid structure can achieve graphene absorption bandwidth of 0.311 μm in near-infrared region with absorption exceeding 30%. We also studied absorption peaks dependence on gratings widths and SiO2 spacer thickness, and explained the results using physical mechanism. Our research can provide a theoretical guidance for future device preparation.展开更多
以正硅酸四乙酯和FeCo为原料,采用改进的Stober工艺制备了FeCo@纳米SiO_(2)。结果表明:制备粉体为均匀核壳结构;当SiO_(2)含量为35%(质量分数)时,样品的最低反射损耗(RL)在厚度为2.6 mm时达到-36.1 dB,有效吸收带宽(RL<-10 d B)为3.2...以正硅酸四乙酯和FeCo为原料,采用改进的Stober工艺制备了FeCo@纳米SiO_(2)。结果表明:制备粉体为均匀核壳结构;当SiO_(2)含量为35%(质量分数)时,样品的最低反射损耗(RL)在厚度为2.6 mm时达到-36.1 dB,有效吸收带宽(RL<-10 d B)为3.2 GHz;当SiO_(2)含量为65%时,样品具有最佳的抗氧化性,升温至800℃,质量增加仅2%。SiO_(2)的包覆不仅优化了FeCo的阻抗匹配,有利于电磁波吸收,而且在高温下SiO_(2)可以阻隔FeCo和氧气接触,增加其抗氧化性。展开更多
文摘As emerging new material, graphene has inspired great research interest. However, most of the studies focused on how to improve the absorption efficiency of graphene, but payed little attention on broadening absorption bandwidth while ensuring high absorption efficiency. In this work, we proposed a hybrid nanostructure, which not only can improve absorption efficiency but also can increase absorption bandwidth. The proposed hybrid nanostructure consists of a monolayer graphene sandwiched between three Ag gratings with different widths and a SiO2 spacer on a Ag substrate, these three gratings and substrate can excite three independent magnetic dipole resonances. In our calculations, we numerically demonstrate the proposed hybrid structure can achieve graphene absorption bandwidth of 0.311 μm in near-infrared region with absorption exceeding 30%. We also studied absorption peaks dependence on gratings widths and SiO2 spacer thickness, and explained the results using physical mechanism. Our research can provide a theoretical guidance for future device preparation.
基金National Natural Science Foundation of China(Nos. 61575008,61650404)the Public Welfare Technology Research Project of Zhejiang Province(No. LGC21E050002)the Quzhou Science and Technology Project(No. 2019K20)。
