We investigate theoretically the spin caloritronic transport properties of a stable 1,3,5-triphenylverdazyl （TPV） radical sandwiched between Au electrodes through different connection fashions. Obvious spin Seebeck ...We investigate theoretically the spin caloritronic transport properties of a stable 1,3,5-triphenylverdazyl （TPV） radical sandwiched between Au electrodes through different connection fashions. Obvious spin Seebeck effect can be observed in the para-eonnection fashion. Furthermore, a pure spin current and a completely spin-polarized current can be realized by tuning the gate voltage. Furthermore, a 100% spin polarization without the need of gate voltage can be obtained in the meta-conneetion fashion. These results demonstrate that TPV radical is a promising material for spin caloritronic and spintronic applications.展开更多
Using first-principles density functional theory combined with nonequilibrium Green＇s function method, we inves-tigate the spin caloritronic transport properties of （2×1） reconstructed zigzag MoS2 nanoribbons....Using first-principles density functional theory combined with nonequilibrium Green＇s function method, we inves-tigate the spin caloritronic transport properties of （2×1） reconstructed zigzag MoS2 nanoribbons. These systems can exhibit obvious spin Seebeck effect. Furthermore, by tuning the external magnetic field, a thermal giant magnetoresistance up to 10^4% can be achieved. These spin caloritronic transport properties are understood in terms of spin-resolved transmission spectra, band structures, and the symmetry analyses of energy bands around the Fermi level.展开更多
The spin caloritronic properties of the Janus VSTe monolayer were investigated using density functional theory(DFT)and the non-equilibrium Green’s function(NEGF)method,implemented in the Atomistix Toolkit(ATK)package...The spin caloritronic properties of the Janus VSTe monolayer were investigated using density functional theory(DFT)and the non-equilibrium Green’s function(NEGF)method,implemented in the Atomistix Toolkit(ATK)package.Our study revealed significant spin-splitting within the Janus VSTe monolayer,which induced spin currents under a temperature gradient across the device.By applying a 1%tensile strain,the Janus VSTe monolayer exhibited a perfect thermal spin filtering effect(SFE),with the spin-up current nearly suppressed to zero.Both the unstrained and strained Janus VSTe monolayers demonstrated excellent spin caloritronic properties,with spin figures of merit of 10.915 and 8.432 at an average temperature of 100 K,respectively.Notably,these properties were found to be sensitive to temperature,performing optimally at lower temperatures.These results suggest a promising avenue for designing spin caloritronic devices aimed at efficient waste heat recovery.展开更多
Heat dissipation is one of the most serious problems in modern integrated electronics with the continuously decreasing devices size. Large portion of the consumed power is inevitably dissipated inthe form of waste hea...Heat dissipation is one of the most serious problems in modern integrated electronics with the continuously decreasing devices size. Large portion of the consumed power is inevitably dissipated inthe form of waste heat which not only restricts the device energy-efficiency performance itself, butalso leads to severe environment problems and energy crisis. Thermoelectric Seebeck effect is a greenenergy-recycling method, while thermoelectric Peltier effect can be employed for heat management byactively cooling overheated devices, where passive cooling by heat conduction is not sufficiently enough.However, the technological applications of thermoelectricity are limited so far by their very low conversion efficiencies and lack of deep understanding of thermoelectricity in microscopic levels. Probingand managing the thermoelectricity is therefore fundamentally important particularly in nanoscale. Inthis short review, we will first briefly introduce the microscopic techniques for studying nanoscale thermoelectricity, focusing mainly on scanning thermal microscopy (SThM). SThM is a powerful tool formapping the lattice heat with nanometer spatial resolution and hence detecting the nanoscale thermaltransport and dissipation processes. Then we will review recent experiments utilizing these techniques to investigate thermoelectricity in various nanomaterial systems including both (two-material)heterojunctions and (single-material) homojunctions with tailored Seebeck coefficients, and also spinSeebeck and Peltier effects in magnetic materials. Next, we will provide a perspective on the promisingapplications of our recently developed Scanning Noise Microscope (SNoiM) for directly probing thenon-equilibrium transporting hot charges (instead of lattice heat) in thermoelectric devices. SNoiMtogether with SThM are expected to be able to provide more complete and comprehensive understanding to the microscopic mechanisms in thermoelectrics. Finally, we make a conclusion and outlook onthe future development of microscopic studies in thermoelectrics.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11104115the Science Foundation of Middle-aged and Young Scientist of Shandong Province of China under Grant No BS2013DX036
文摘We investigate theoretically the spin caloritronic transport properties of a stable 1,3,5-triphenylverdazyl （TPV） radical sandwiched between Au electrodes through different connection fashions. Obvious spin Seebeck effect can be observed in the para-eonnection fashion. Furthermore, a pure spin current and a completely spin-polarized current can be realized by tuning the gate voltage. Furthermore, a 100% spin polarization without the need of gate voltage can be obtained in the meta-conneetion fashion. These results demonstrate that TPV radical is a promising material for spin caloritronic and spintronic applications.
基金Supported by the Natural Science Foundation of Shandong Province under Grant No ZR2016AM11
文摘Using first-principles density functional theory combined with nonequilibrium Green＇s function method, we inves-tigate the spin caloritronic transport properties of （2×1） reconstructed zigzag MoS2 nanoribbons. These systems can exhibit obvious spin Seebeck effect. Furthermore, by tuning the external magnetic field, a thermal giant magnetoresistance up to 10^4% can be achieved. These spin caloritronic transport properties are understood in terms of spin-resolved transmission spectra, band structures, and the symmetry analyses of energy bands around the Fermi level.
基金Project(2022JJ30049)supported by the Natural Science Foundation of Hunan Province,China。
文摘The spin caloritronic properties of the Janus VSTe monolayer were investigated using density functional theory(DFT)and the non-equilibrium Green’s function(NEGF)method,implemented in the Atomistix Toolkit(ATK)package.Our study revealed significant spin-splitting within the Janus VSTe monolayer,which induced spin currents under a temperature gradient across the device.By applying a 1%tensile strain,the Janus VSTe monolayer exhibited a perfect thermal spin filtering effect(SFE),with the spin-up current nearly suppressed to zero.Both the unstrained and strained Janus VSTe monolayers demonstrated excellent spin caloritronic properties,with spin figures of merit of 10.915 and 8.432 at an average temperature of 100 K,respectively.Notably,these properties were found to be sensitive to temperature,performing optimally at lower temperatures.These results suggest a promising avenue for designing spin caloritronic devices aimed at efficient waste heat recovery.
基金support from Shanghai Science and Technology Committee under grant Nos.20JC1414700,18JC1420402,18JC1410300the National Natural Science Foundation of China(NSFC)under grant Nos.11991060/11674070/11634012the National Key Research Program of China under grant No.2016YFA0302000.
文摘Heat dissipation is one of the most serious problems in modern integrated electronics with the continuously decreasing devices size. Large portion of the consumed power is inevitably dissipated inthe form of waste heat which not only restricts the device energy-efficiency performance itself, butalso leads to severe environment problems and energy crisis. Thermoelectric Seebeck effect is a greenenergy-recycling method, while thermoelectric Peltier effect can be employed for heat management byactively cooling overheated devices, where passive cooling by heat conduction is not sufficiently enough.However, the technological applications of thermoelectricity are limited so far by their very low conversion efficiencies and lack of deep understanding of thermoelectricity in microscopic levels. Probingand managing the thermoelectricity is therefore fundamentally important particularly in nanoscale. Inthis short review, we will first briefly introduce the microscopic techniques for studying nanoscale thermoelectricity, focusing mainly on scanning thermal microscopy (SThM). SThM is a powerful tool formapping the lattice heat with nanometer spatial resolution and hence detecting the nanoscale thermaltransport and dissipation processes. Then we will review recent experiments utilizing these techniques to investigate thermoelectricity in various nanomaterial systems including both (two-material)heterojunctions and (single-material) homojunctions with tailored Seebeck coefficients, and also spinSeebeck and Peltier effects in magnetic materials. Next, we will provide a perspective on the promisingapplications of our recently developed Scanning Noise Microscope (SNoiM) for directly probing thenon-equilibrium transporting hot charges (instead of lattice heat) in thermoelectric devices. SNoiMtogether with SThM are expected to be able to provide more complete and comprehensive understanding to the microscopic mechanisms in thermoelectrics. Finally, we make a conclusion and outlook onthe future development of microscopic studies in thermoelectrics.
