The thermal transport properties of NiNB_(2)O_(6)as anode material for lithium-ion battery and the effect of strain were studied by machine learning interatomic potential combined with Boltzmann transport equation.The...The thermal transport properties of NiNB_(2)O_(6)as anode material for lithium-ion battery and the effect of strain were studied by machine learning interatomic potential combined with Boltzmann transport equation.The results show that the lattice thermal conductivity of NiNB_(2)O_(6)along the three crystal directions[100],[010],and[001]are 0.947 W·m^(-1)·K^(-1),0.727 W·m^(-1)·K^(-1),and 0.465 W·m^(-1)·K^(-1),respectively,indicating the anisotropy of the lattice thermal conductivity of NiNB_(2)O_(6).This anisotropy of the lattice thermal conductivity stems from the significant difference of phonon group velocities in different crystal directions of NiNB_(2)O_(6).When the tensile strain is applied along the[001]crystal direction,the lattice thermal conductivity in all three directions decreases.However,when the compressive strain is applied,the lattice thermal conductivity in the[100]and[010]crystal directions is increased,while the lattice thermal conductivity in the[001]crystal direction is abnormally reduced due to the significant inhibition of compressive strain on the group velocity.These indicate that the anisotropy of thermal conductivity of NiNB_(2)O_(6)can be enhanced by the compressive strain,and reduced by the tensile strain.展开更多
We preform a first-principles study of performance of 5 nm double-gated(DG)Schottky-barrier field effect transistors(SBFETs)based on two-dimensional SiC with monolayer or bilayer metallic 1T-phase MoS_(2) contacts.Bec...We preform a first-principles study of performance of 5 nm double-gated(DG)Schottky-barrier field effect transistors(SBFETs)based on two-dimensional SiC with monolayer or bilayer metallic 1T-phase MoS_(2) contacts.Because of the wide bandgap of SiC,the corresponding DG SBFETs can weaken the short channel effect.The calculated transfer characteristics also meet the standard of the high performance transistor summarized by international technology road-map for semiconductors.Moreover,the bilayer metallic 1T-phase MoS_(2) contacts in three stacking structures all can further raise the ON-state currents of DG SiC SBFETs in varying degrees.The above results are helpful and instructive for design of short channel transistors in the future.展开更多
Using the first principles calculation and Boltzmann transport theory, we study the thermoelectric properties of Si2BNadsorbing halogen atoms (Si2BN-4X, X = F, Cl, Br, and I). The results show that the adsorption of h...Using the first principles calculation and Boltzmann transport theory, we study the thermoelectric properties of Si2BNadsorbing halogen atoms (Si2BN-4X, X = F, Cl, Br, and I). The results show that the adsorption of halogen atoms cansignificantly regulate the energy band structure and lattice thermal conductivity of Si2BN. Among them, Si2BN-4I has thebest thermoelectric performance, the figure of merit can reach 0.50 K at 300 K, which is about 16 times greater than that ofSi2BN. This is because the adsorption of iodine atoms not only significantly increases the Seebeck coefficient due to banddegeneracy, but also rapidly reduces the phonon thermal conductivity by enhancing phonon scattering. Our work proves theapplication potential of Si2BN-based crystals in the field of thermoelectricity and the effective method for metal crystals toopen bandgaps by adsorbing halogens.展开更多
基金the National Natural Science Foundation of China(Grant Nos.12074115 and 11874145)the Natural Science Foundation of Hunan Province,China(Grant No.2021JJ30202)。
文摘The thermal transport properties of NiNB_(2)O_(6)as anode material for lithium-ion battery and the effect of strain were studied by machine learning interatomic potential combined with Boltzmann transport equation.The results show that the lattice thermal conductivity of NiNB_(2)O_(6)along the three crystal directions[100],[010],and[001]are 0.947 W·m^(-1)·K^(-1),0.727 W·m^(-1)·K^(-1),and 0.465 W·m^(-1)·K^(-1),respectively,indicating the anisotropy of the lattice thermal conductivity of NiNB_(2)O_(6).This anisotropy of the lattice thermal conductivity stems from the significant difference of phonon group velocities in different crystal directions of NiNB_(2)O_(6).When the tensile strain is applied along the[001]crystal direction,the lattice thermal conductivity in all three directions decreases.However,when the compressive strain is applied,the lattice thermal conductivity in the[100]and[010]crystal directions is increased,while the lattice thermal conductivity in the[001]crystal direction is abnormally reduced due to the significant inhibition of compressive strain on the group velocity.These indicate that the anisotropy of thermal conductivity of NiNB_(2)O_(6)can be enhanced by the compressive strain,and reduced by the tensile strain.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12074046 and 12074115)the Hunan Provincial Natural Science Foundation of China(Grant Nos.2020JJ4597,2021JJ40558,and 2021JJ30733)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department,China(Grant Nos.20K007 and 20C0039)the Key Projects of Changsha Science and Technology Plan(Grant No.kq1901102).
文摘We preform a first-principles study of performance of 5 nm double-gated(DG)Schottky-barrier field effect transistors(SBFETs)based on two-dimensional SiC with monolayer or bilayer metallic 1T-phase MoS_(2) contacts.Because of the wide bandgap of SiC,the corresponding DG SBFETs can weaken the short channel effect.The calculated transfer characteristics also meet the standard of the high performance transistor summarized by international technology road-map for semiconductors.Moreover,the bilayer metallic 1T-phase MoS_(2) contacts in three stacking structures all can further raise the ON-state currents of DG SiC SBFETs in varying degrees.The above results are helpful and instructive for design of short channel transistors in the future.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12074115,11874145,and 51775183)the Hunan Provincial Natural Science Fund of China(Grant No.2018JJ2125).
文摘Using the first principles calculation and Boltzmann transport theory, we study the thermoelectric properties of Si2BNadsorbing halogen atoms (Si2BN-4X, X = F, Cl, Br, and I). The results show that the adsorption of halogen atoms cansignificantly regulate the energy band structure and lattice thermal conductivity of Si2BN. Among them, Si2BN-4I has thebest thermoelectric performance, the figure of merit can reach 0.50 K at 300 K, which is about 16 times greater than that ofSi2BN. This is because the adsorption of iodine atoms not only significantly increases the Seebeck coefficient due to banddegeneracy, but also rapidly reduces the phonon thermal conductivity by enhancing phonon scattering. Our work proves theapplication potential of Si2BN-based crystals in the field of thermoelectricity and the effective method for metal crystals toopen bandgaps by adsorbing halogens.
