Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal,although having a fixed absorption performance limits their applicability.Here,a simple,transparent...Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal,although having a fixed absorption performance limits their applicability.Here,a simple,transparent,and thermally tunable microwave absorber is proposed,based on a patterned vanadium dioxide(VO_(2))film.Numerical calculations and experiments demonstrate that the proposed VO_(2)absorber has a high optical transmittance of 84.9%at 620 nm;its reflection loss at 15.06 GHz can be thermally tuned from–4.257 to–60.179 dB,and near-unity absorption is achieved at 523.750 K.Adjusting only the patterned VO_(2)film duty cycle can change the temperature of near-unity absorption.Our VO_(2)absorber has a simple composition,a high optical transmittance,a thermally tunable microwave absorption performance,a large modulation depth,and an adjustable temperature tuning range,making it promising for application in tunable sensors,thermal emitters,modulators,thermal imaging,bolometers,and photovoltaic devices.展开更多
Finding the optimal optoelectronic properties(zero-order optical transmittance,shielding effectiveness,and stray light uniformity)of metallic mesh is significant for its application in electromagnetic interference shi...Finding the optimal optoelectronic properties(zero-order optical transmittance,shielding effectiveness,and stray light uniformity)of metallic mesh is significant for its application in electromagnetic interference shielding areas.However,there are few relevant studies at present.Based on optoelectronic properties,we propose a comprehensive evaluation factor Q,which is simple in form and can be used to evaluate the mesh with different parameters in a simple and efficient way.The effectivity of Q is verified by comparing the trend of Q values with the evaluation results of the technique for order preference by similarity to ideal solution(TOPSIS).The evaluation factor Q can also be extended to evaluate the optoelectronic properties of different kinds of metallic meshes,which makes it extremely favorable for metallic mesh design and application.展开更多
Two-dimensional(2D)magnetic materials are essential for the development of the next-generation spintronic technologies.Recently,layered van der Waals(vdW)compound MnBi2Te4(MBT)has attracted great interest,and its 2D s...Two-dimensional(2D)magnetic materials are essential for the development of the next-generation spintronic technologies.Recently,layered van der Waals(vdW)compound MnBi2Te4(MBT)has attracted great interest,and its 2D structure has been reported to host coexisting magnetism and topology.Here,we design several conceptual nanodevices based on MBT monolayer(MBT-ML)and reveal their spin-dependent transport properties by means of the first-principles calculations.The pn-junction diodes and sub-3-nm pin-junction field-effect transistors(FETs)show a strong rectifying effect and a spin filtering effect,with an ideality factor n close to 1 even at a reasonably high temperature.In addition,the pip-and nin-junction FETs give an interesting negative differential resistive(NDR)effect.The gate voltages can tune currents through these FETs in a large range.Furthermore,the MBT-ML has a strong response to light.Our results uncover the multifunctional nature of MBT-ML,pave the road for its applications in diverse next-generation semiconductor spin electric devices.展开更多
基金support from the National Natural Science Foundation of China(61975046)。
文摘Transparent microwave absorbers that exhibit high optical transmittance and microwave absorption capability are ideal,although having a fixed absorption performance limits their applicability.Here,a simple,transparent,and thermally tunable microwave absorber is proposed,based on a patterned vanadium dioxide(VO_(2))film.Numerical calculations and experiments demonstrate that the proposed VO_(2)absorber has a high optical transmittance of 84.9%at 620 nm;its reflection loss at 15.06 GHz can be thermally tuned from–4.257 to–60.179 dB,and near-unity absorption is achieved at 523.750 K.Adjusting only the patterned VO_(2)film duty cycle can change the temperature of near-unity absorption.Our VO_(2)absorber has a simple composition,a high optical transmittance,a thermally tunable microwave absorption performance,a large modulation depth,and an adjustable temperature tuning range,making it promising for application in tunable sensors,thermal emitters,modulators,thermal imaging,bolometers,and photovoltaic devices.
基金Project supported by the National Natural Science Foundation of China(No.61975046)。
文摘Finding the optimal optoelectronic properties(zero-order optical transmittance,shielding effectiveness,and stray light uniformity)of metallic mesh is significant for its application in electromagnetic interference shielding areas.However,there are few relevant studies at present.Based on optoelectronic properties,we propose a comprehensive evaluation factor Q,which is simple in form and can be used to evaluate the mesh with different parameters in a simple and efficient way.The effectivity of Q is verified by comparing the trend of Q values with the evaluation results of the technique for order preference by similarity to ideal solution(TOPSIS).The evaluation factor Q can also be extended to evaluate the optoelectronic properties of different kinds of metallic meshes,which makes it extremely favorable for metallic mesh design and application.
基金We acknowledge funding from the National Natural Science Foundation of China(Nos.11774079 and 61774059)the Scientific and Technological Innovation Program of Henan Province’s Universities(No.20HASTIT026)+4 种基金the Natural Science Foundation of Henan(No.202300410226)the Natural Science Foundation of Henan Normal University(No.2020PL15)the Henan Overseas Expertise Introduction Center for Discipline Innovation(No.CXJD2019005)the HPCC of HNU.RW acknowledges funding from the US DOE-BES(No.DE-FG02-05ER46237)We thank F.Xue at Tsinghua University,W.Ju and D.Kang at HNUST for helpful discussions.
文摘Two-dimensional(2D)magnetic materials are essential for the development of the next-generation spintronic technologies.Recently,layered van der Waals(vdW)compound MnBi2Te4(MBT)has attracted great interest,and its 2D structure has been reported to host coexisting magnetism and topology.Here,we design several conceptual nanodevices based on MBT monolayer(MBT-ML)and reveal their spin-dependent transport properties by means of the first-principles calculations.The pn-junction diodes and sub-3-nm pin-junction field-effect transistors(FETs)show a strong rectifying effect and a spin filtering effect,with an ideality factor n close to 1 even at a reasonably high temperature.In addition,the pip-and nin-junction FETs give an interesting negative differential resistive(NDR)effect.The gate voltages can tune currents through these FETs in a large range.Furthermore,the MBT-ML has a strong response to light.Our results uncover the multifunctional nature of MBT-ML,pave the road for its applications in diverse next-generation semiconductor spin electric devices.
