Related papers: Thermopower in p-type GaAs/AlGaAs layers
We calculate the low temperature resistivity in low density 2D hole gases in GaAs heterostructures by including screened charged impurity and phonon scattering in the theory. Our calculated resistance, which shows striking temperature…
We present inverted metamorphic Ga0.3In0.7As photovoltaic converters with sub-0.60 eV bandgaps grown on InP and GaAs substrates. The compositionally graded buffers in these devices have threading dislocation densities of 1.3x10^6 cm^-2 and…
Room temperature electronic diffusion is studied in 3 mum thick epitaxial p+ GaAs lift-off films using a novel circularly polarized photoluminescence microscope. The method is equivalent to using a standard optical microscope and provides a…
The thermopower and conductance of atomic-size metallic contacts have been simultaneously measured using a mechanically controllable break junction. For contacts approaching atomic dimensions, abrupt steps in the thermopower are observed…
We apply the non-perturbative optimized linear $\delta$ expansion method to the O(N) scalar field model in three-dimensions to determine the transition temperature of a dilute homogeneous Bose gas. Our results show that the shift of the…
The swelling dynamics of polymer gels are characterized by the (collective) diffusion coefficient $D$ of the polymer network. Here, we measure the temperature dependence of $D$ of polymer gels with controlled homogeneous network structures…
Precise calorimetric measurements have been carried out in the 7 - 300 K temperature range on two ceramic samples of thulium 123 cuprates TmBa2Cu3O6.92 and TmBa2Cu3O6.70. The temperature dependence of the heat capacity was analyzed in the…
The effects of Rh doping on the thermoelectric properties of Pt1-xRhxAs2 (x = 0, 0.005, and 0.01) with pyrite structure were studied by conducting measurements of electrical resistivity rho, Seebeck coefficient S, and thermal conductivity…
The parameters of two-dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure were determined by an acoustical (contactless) method in the delocalized electrons region ($B\le$2.5T). Nonlinear effects in Surface Acoustic Wave (SAW)…
We introduce a thermodynamical model based on the two-temperature approach in order to fully understand the dynamics of the coherent A$_{1g}$ phonon in laser-excited bismuth. Using this model, we simulate the time evolution of (111) Bragg…
At low temperature using thermodynamics of irreversible processes the general expressions for the temperature dependence of the thermopower in the case of the hopping conductivity for disordered materials are found. The account of influence…
Electron transport in suspended and non-suspended GaAs point contacts (PCs) of different widths is experimentally studied. The superballistic contribution to the conductance, that demonstrates a distinctive quadratic dependence on the PC…
SnSe is a topical thermoelectric material with a low thermal conductivity which is linked to its unique crystal structure. We use low-temperature heat capacity measurements to demonstrate the presence of two characteristic vibrational…
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…
We report the thermal conductance G of Au/Ti/graphene/SiO2 interfaces (graphene layers 1 < n < 10) typical of graphene transistor contacts. We find G ~ 25 MW m-2 K-1 at room temperature, four times smaller than the thermal conductance of a…
We present an analysis of the thin layer of Galactic warm ionized gas at an angular resolution ~ 10'. This is carried out using radio continuum data at 1.4 GHz, 2.7 GHz and 5 GHz in the coordinate region 20 < l < 30 deg, -1.5 < b < +1.5…
Inelastic light scattering spectra of Bi_2Se_3 and Sb_2Te_3 single crystals have been measured over the temperature range from 5 K to 300 K. The temperature dependence of dominant A^{2}_{1g} phonons shows similar behavior in both materials.…
We present a general harmonic theory for the temperature dependence of phonon-renormalized properties of solids. Firstly, we formulate a perturbation theory in phonon-phonon interactions to calculate the phonon renormalization of physical…
Using direct atomic simulations, the vibration scattering time scales are characterized, and then the nature and the quantitative weight of thermal excitations are investigated in an example system Li2S from its amorphous solid state to its…
At extreme strain rates, where fast moving dislocations govern plastic deformation, anharmonic phonon scattering imparts a drag force on the dislocations. In this paper, we present calculations of the dislocation drag coefficients of…