相关论文: Diameter dependence of SiGe nanowire thermal condu…
Dimensional dependence of thermal conductance at low temperatures in nanowires is studied using the nonequilibrium Green's function (NEGF) method. Our calculation shows a smooth dimensional crossover of thermal conductance in nanowire from…
The lattice thermal conductivity of crystalline Si nanowires is calculated. The calculation uses complete phonon dispersions, and does not require any externally imposed frequency cutoffs. No adjustment to nanowire thermal conductivity…
We study the size dependence of thermal conductivity in nanoscale semiconducting systems. An analytical formula including the surface scattering and the size confinement effects of phonon transport is derived. The theoretical formula gives…
Electrical conductance through InAs nanowires is relevant for electronic applications as well as for fundamental quantum experiments. Here we employ nominally undoped, slightly tapered InAs nanowires to study the diameter dependence of…
We have used an atomistic {\it ab initio} approach with no adjustable parameters to compute the lattice thermal conductivity of Si$_{0.5}$Ge$_{0.5}$ with a low concentration of embedded Si or Ge nanoparticles of diameters up to 4.4 nm.…
We investigate the possibility to obtain a thermal diode with functionally graded Si-Ge alloys. A wire with variable section is considered. After the introduction of a formula giving the thermal conductivity of the wire as a function of the…
We investigate temperature dependent thermal conductivity k(T) in a single Ge nanowire (NW) using Optothermal Raman Spectroscopy which utilizes the temperature dependence of Raman lines as a local probe for temperature. The experiment was…
By using first-principles tight-binding electronic structure calculation and Boltzmann transport equation, we investigate the size dependence of thermoelectric properties of silicon nanowires (SiNWs). With cross section area increasing, the…
The thermoelectric properties of two typical SiGe nanotubes are investigated using a combination of density functional theory, Boltzmann transport theory, and molecular dynamics simulations. Unlike carbon nanotubes, these SiGe nanotubes…
By using molecular dynamics simulations, we study thermal conductivity of silicon nanowires (SiNWs) with different cross sectional geometries. It is found that thermal conductivity decreases monotonically with the increase of…
The ability to engineer the thermal conductivity of materials allows us to control the flow of heat and derive novel functionalities such as thermal rectification, thermal switching, and thermal cloaking. While this could be achieved by…
We have performed thermal conductance measurements on individual single crystalline silicon suspended nanowires. The nanowires (130 nm thick and 200 nm wide) are fabricated by e-beam lithography and suspended between two separated pads on…
We report measurements of electronic, thermoelectric, and galvanomagnetic properties of individual single crystal antimony telluride (Sb2Te3) nanowires with diameters in the range of 20-100 nm. Temperature dependent resistivity and…
Pure amorphous solids are traditionally considered to set the lower bound of thermal conductivity due to their disordered atomic structure that impedes vibrational energy transport. However, the lower limits for thermal conductivity in…
We present a calculation of the lattice thermal conductivity of Si-Ge nanowires (NWs), based on solving the Boltzmann transport equation by the Monte Carlo method of sampling the phonon mean free paths. We augment the previous work with the…
Low dimensional systems, nanowires, in particular, have exhibited excellent optical and electronic properties. Understanding the thermal properties in semiconductor nanowires is very important for their applications in their electronic…
Porous nanowires (NWs) with tunable thermal conductance are examined as a candidate for thermoelectric (TE) devices with high efficiency (ZT). Thermal conductance of porous Si and Ge NWs is calculated using the complete phonon dispersion…
We present results of a Au-Ge alloy that is useful as a resistance-based thermometer from room temperature down to at least \SI{0.2}{\kelvin}. Over a wide range, the electrical resistivity of the alloy shows a logarithmic temperature…
Phonon properties of small Si nanowires in [110] direction have been analyzed using density functional perturbation theory. Several samples with varying diameters ranging from 0.38 to 1.5 nm have been calculated. It is found that the…
We present a non-invasive technique for measuring the thermal conductivity of fragile and sensitive materials. In the context of planet formation research, the investigation of the thermal conductivity of porous dust aggregates provide…