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Showing 1 to 7 of 7 for “"SiGe alloys"”.
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First-principles study of phonon drag effect in SiGe alloys
Thermoelectric materials with large figures of merit zT ([mathematical equation], where S, T, [sigma], K are the Seebeck coefficient, absolute temperature, electrical conductivity and thermal conductivity) are promising candidate materials for efficient solid-state devices for electricity …
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Experimental study of thermal conductivity reduction of silicon-germanium nanocomposite for thermoelastic application
… conversion efficiency of silicon germanium (SiGe), two methods were used to decrease the thermal conductivity by increasing phonon boundary scattering at interfaces. In the first method, SiGe alloys were annealed at a temperature higher than the melting point to increase the number of grain …
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Thermoelectric Energy Conversion: First-principles Simulations, Energy Harvesting and Deep Cooling Systems
… of all thermoelectric transport properties of SiGe alloys over wide ranges of compositions, doping levels, and temperatures. This is the first time we are able to simulate realistic thermoelectric materials from first principles without fitting parameters. Surprisingly, the phonon drag effect …
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Growth of silicon(1-x) germanium(x) from disilane and digermane by gas-source molecular beam epitaxy
… Ge\sb2H\sb6,$ respectively. The growth rate of SiGe alloys R$\sb{\rm SiGe}$ as a function of the bulk Ge content x was found to be a complex. In the surface-reaction-limited regime, R$\sb{\rm SiGe}$ increased with Ge surface coverage $\theta\sb{\rm Ge}$ due to the lower activation energy of …
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Thermal transport at the nanoscale : from fourier diffusion to phonon hydrodynamics
… the diffusive regime of thermal transport in SiGe alloys, thereby extending current theory and experiment to the study of size effects in thermal transport to opaque materials. Finally, we go beyond the single mode approximation to the Boltzmann transport equation and develop a formalism to …
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Synthesis and Characterization of Si, Ge, and SixGe1-x Nanowires by Fiber Drawing
… below 100nm in diameter. For the first time SiGe alloys are produced in optical fiber from a mixture of the two powders across the entire compositional range. A discussion of the properties of silicon and germanium and their alloys is given with emphasis on the differences between properties …
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Thermoelectric properties of silicon-germanium alloys
… of nano-sized powders. In this thesis, SiGe nanocomposites are investigated for various parameters, such as thermal conductivity, electrical conductivity and Seebeck coefficient, which are needed for thermoelectrics. Grain boundaries in nanocomposites can scatter phonons, when their mean …