Browsing by Subject "Inelastic scattering"

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    Energy relaxation of electrons in InGaN quantum wells
    (Springer New York LLC, 2015-04) Sarikavak-Lisesivdin, B.; Lisesivdin, S. B.; Balkan, N.; Atmaca, G.; Narin, P.; Cakmak, H.; Özbay, Ekmel
    In this study, electron energy relaxation mechanisms in HEMT structures with different InxGa1−xN-channel quantum well (QW) widths are investigated. Theoretical value of the inelastic scattering rates is carried out at electron temperatures between 30 K (−243 °C) < Te < 700 K (427 °C). We used both the experimentally determined and calculated electron temperatures to estimate the energy relaxation rates of non-equilibrium electrons. In wide InGaN QWs, power loss of an electron is shown to be significantly smaller than that in the narrower QWs. © 2015, The Minerals, Metals & Materials Society and ASM International.
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    Non-linear thermoelectricity and cooling effects in metallic constrictions
    (Institute of Physics Publishing Ltd., 1994) Kulik, I. O.
    Linear as well as non-linear contributions to the Zeebeck and Peltier coefficients of a metallic film in contact with the equilibrium metal are calculated within a simple model. The non-linear part of the thermoelectric response survives down to a very low temperature which in principle permits thermoelectric cooling at these conditions. Thermal equilibrium in a metallic constriction between dissimilar metals is evaluated in the non-linear current-carrying regime.
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    Nonlinear phenomena in metallic contacts
    (Springer, 2000) Kulik, Igor O.; Kulik, Igor O.; Ellialtioğlu, Recai
    We review and extend theoretical approaches to nonlinear and nonequilibrium effects in metallic microcontacts ranging in their dimension from the atomic to macroscopic sizes. Atomic contacts are shown to quantize their conductance in units of 2e2/h provided the charge redistributes near the constriction to establish the maximal electron transmittivity through the orifice. Ballistic semiclassical contacts are treated both from the Landauer point of view and from the Boltzmann transport theory. The J-V nonlinearity in contacts is related to the inelastic scattering near the narrowest part of the constriction and permits for spectroscopic investigation of phonons in solids (the point-contact spectroscopy).The effects of phonon emission and reabsorption in contacts are taken into consideration. Phonon relaxation is shown to determine the frequency dependence of the nonlinear contact conductivity. Thermal contacts develop specific nonequilibrium states with hot spots in the center of metallic constriction whose temperature is much in excess of the ambient contact temperature and is uniquely related to voltage.