We calculated the room-temperature phonon thermal conductivity and phonon spectrum of alkyl group-functionalized zigzag graphene nanoribbons(ZGNRs)with molecular dynamics simulations.The increase in both chain length ...We calculated the room-temperature phonon thermal conductivity and phonon spectrum of alkyl group-functionalized zigzag graphene nanoribbons(ZGNRs)with molecular dynamics simulations.The increase in both chain length and concentration of alkyl groups caused remarkable reduction of phonon thermal conductivity in functionalized ZGNRs.Phonon spectra analysis showed that functionalization of ZGNR with alkyl functional groups induced phonon–structural defect scattering,thus leading to the reduction of phonon thermal conductivity of ZGNR.Our study showed that surface functionalization is an effective routine to tune the phonon thermal conductivity of GNRs,which is useful in graphene thermal-related applications.展开更多
Noble metal nanoparticles with localized surface plasmon resonance （LSPR） properties are widely used as optical sensors in biochemical detection and medical diagnosis. In this paper, we propose an effective determin...Noble metal nanoparticles with localized surface plasmon resonance （LSPR） properties are widely used as optical sensors in biochemical detection and medical diagnosis. In this paper, we propose an effective determination method to measure the LSPR absorption intensity of gold nanorods （GNRs）. A near-infrared （NIR） imaging system is established, and an NIR absorption image of the multiple samples of the colloidal GNRs is captured. Then, the LSPR absorption intensities of these samples are obtained by calculating the average grayscale of the target areas based on the NIR image processing technology. By using this method, the LSPR absorption intensities of the multiple samples are determined all at once, and their accuracy is as high as that obtained by using spectrophotometry. These results suggest that this method is an efficient multi-channel determination technique with high-throughput sensing applications.展开更多
Based on the tight-binding approach and the nonequilibrium Green's function method,the thermoelectric performance of graphene nanoribbons(GNRs) and graphene rings are investigated systematically.Thermoelectric pro...Based on the tight-binding approach and the nonequilibrium Green's function method,the thermoelectric performance of graphene nanoribbons(GNRs) and graphene rings are investigated systematically.Thermoelectric properties show substantial dependence on graphene structure.The maximum value of thermoelectric figure of merit(ZT) in perfect GNRs declines exponentially with the increase of width JV except for metallic armchair GNRs with JV = 3/ + 2(i is an integer).In graphene rings,the ZT value is enhanced dramatically at room temperature,which oscillates with perpendicular magnetic field due to Aharonov-Bohm effect.The significantly enhanced ZT value makes graphene ring a promising candidate for thermoelectric applications.展开更多
In order to explore the transport properties of nonsymmetric three-terminal T-shaped graphene nanoribbons (GNRs) devices,the nonequilibrium Green's function method and Landauer-Buttiker formula were adopted. It sh...In order to explore the transport properties of nonsymmetric three-terminal T-shaped graphene nanoribbons (GNRs) devices,the nonequilibrium Green's function method and Landauer-Buttiker formula were adopted. It shows that the transport properties of T-shaped GNRs are highly sensitive to the details of the leads. The T-shaped GNRs show metallic characteristics when electrons transmit from the metallic GNRs lead to the metallic GNRs lead, while the T-shaped GNRs show semiconducting characteristics when electrons transmit from the metallic GNRs lead to the semiconducting GNRs lead. The conductance between the random two leads can be adjusted by varying the size of the leads.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11504418)China Scholarship Council Scholarship Program(Grant No.201706425053)the Fundamental Research Funds for the Central Universities of China(Grant No.2015XKMS075)
文摘We calculated the room-temperature phonon thermal conductivity and phonon spectrum of alkyl group-functionalized zigzag graphene nanoribbons(ZGNRs)with molecular dynamics simulations.The increase in both chain length and concentration of alkyl groups caused remarkable reduction of phonon thermal conductivity in functionalized ZGNRs.Phonon spectra analysis showed that functionalization of ZGNR with alkyl functional groups induced phonon–structural defect scattering,thus leading to the reduction of phonon thermal conductivity of ZGNR.Our study showed that surface functionalization is an effective routine to tune the phonon thermal conductivity of GNRs,which is useful in graphene thermal-related applications.
基金Supported by the Natural Science Foundation of Jiangsu Province(SBK201240182)
文摘Noble metal nanoparticles with localized surface plasmon resonance （LSPR） properties are widely used as optical sensors in biochemical detection and medical diagnosis. In this paper, we propose an effective determination method to measure the LSPR absorption intensity of gold nanorods （GNRs）. A near-infrared （NIR） imaging system is established, and an NIR absorption image of the multiple samples of the colloidal GNRs is captured. Then, the LSPR absorption intensities of these samples are obtained by calculating the average grayscale of the target areas based on the NIR image processing technology. By using this method, the LSPR absorption intensities of the multiple samples are determined all at once, and their accuracy is as high as that obtained by using spectrophotometry. These results suggest that this method is an efficient multi-channel determination technique with high-throughput sensing applications.
基金National Natural Science Foundations of China(Nos.11174242,11404278,11204265)Natural Science Foundation of Jiangsu Province,China(No.BK2012248)Scientific Research Foundation of Yancheng Institute of Technology,China(No.KJC2014024)
文摘Based on the tight-binding approach and the nonequilibrium Green's function method,the thermoelectric performance of graphene nanoribbons(GNRs) and graphene rings are investigated systematically.Thermoelectric properties show substantial dependence on graphene structure.The maximum value of thermoelectric figure of merit(ZT) in perfect GNRs declines exponentially with the increase of width JV except for metallic armchair GNRs with JV = 3/ + 2(i is an integer).In graphene rings,the ZT value is enhanced dramatically at room temperature,which oscillates with perpendicular magnetic field due to Aharonov-Bohm effect.The significantly enhanced ZT value makes graphene ring a promising candidate for thermoelectric applications.
基金National Natural Science Foundation of China(No.11174242)The Fund of Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province,China(No.AE201021)+1 种基金The Natural Science Fund for Colleges and Universities in Jiangsu Province,China(No.11KJB140012)Open Project of Key Laboratory for Ecological-Environment Materials of Jiangsu Province,China(No.EML2012012)
文摘In order to explore the transport properties of nonsymmetric three-terminal T-shaped graphene nanoribbons (GNRs) devices,the nonequilibrium Green's function method and Landauer-Buttiker formula were adopted. It shows that the transport properties of T-shaped GNRs are highly sensitive to the details of the leads. The T-shaped GNRs show metallic characteristics when electrons transmit from the metallic GNRs lead to the metallic GNRs lead, while the T-shaped GNRs show semiconducting characteristics when electrons transmit from the metallic GNRs lead to the semiconducting GNRs lead. The conductance between the random two leads can be adjusted by varying the size of the leads.
