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 lengt...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
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
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.
