Related papers: Concept study for a high-efficiency nanowire-based…
The authors use two insulator layers in thermotunnel refrigerator to modify the shape of the tunneling barrier so that electrons with high kinetic energy pass it with increased probability. Theoretical analysis show that the overall…
We compute atomistically the heat conductance for ultra-thin pristine silicon nanowires (SiNWs) with diameters ranging from 1 to 5 nm. The room temperature thermal conductance is found to be highly anisotropic: wires oriented along the…
Due to its low bandgap and high optical efficiency, tellurium is considered an important material candidate for mid-infrared applications. Taking advantage of its structural anisotropy, we fabricated tellurium nanowire devices and…
Power and efficiency of heat engines are two conflicting objectives, and a tight efficiency bound is expected to give insights on the fundamental properties of the power-efficiency tradeoff. Here we derive an upper bound on the efficiency…
Boundary-engineering in nanostructures has the potential to dramatically impact the development of materials for high-efficiency conversion of thermal energy directly into electricity. In particular, nanostructuring of semiconductors can…
Integration of high quality semiconductor-superconductor devices into scalable and CMOS compatible architectures remains an outstanding challenge, currently hindering their practical implementation. Here, we demonstrate growth of InAs…
Controlling thermal transport at the nanoscale is vital for many applications. Previously, it has been shown that this control can be achieved with periodically nanostructured two-dimensional phononic crystals, for the case of suspended…
An important goal in nanoelectromechanics is to cool the vibrational motion, ideally to its quantum ground state. Cooling by an applied charge current is a particularly simple and hence attractive strategy to this effect. Here, we explore…
Following demands for materials with peculiar transport properties, e.g. in magnetoelectronics or thermoelectrics, there is a need for materials modeling at the quantum-mechanical level. We combine density-functional with various…
Ferroelectrics are essential in low-dimensional memory devices for multi-bit storage and high-density integration. A polar structure is a necessary premise for ferroelectricity, mainly existing in compounds. However, it is usually rare in…
In this dissertation, thermal and electrical properties of aligned multiwall carbon nanotubes (MWNTs) prepared by thermal decomposition of hydrocarbons have been experimentally studied. The thesis consists of six chapters. Ch1 is an…
We theoretically show that a thermophotovoltaic (TPV) system enhanced by a wire metamaterial opens the door to a prospective microgap thermophotovoltaics which will combine high electric output with relatively low temperatures of the…
The widely debated feasibility of thermodynamic machines achieving Carnot efficiency at finite power has been convincingly dismissed. Yet, the common wisdom that efficiency can only be optimal in the limit of infinitely-slow processes…
A two-site nanostructure (e.g, a "molecule") bridging two conducting leads and connected to a phonon bath is considered. The two relevant levels closest to the Fermi energy are connected each to its lead. The leads have slightly different…
We use Transient Rayleigh Scattering to study the thermalization of hot photoexcited carriers in single GaAsSb/InP nanowire heterostructures. By comparing the energy loss rate in single bare GaAsSb nanowires which do not show substantial…
Effects of ballistic transport on the temperature profiles and thermal resistance in nanowires are studied. Computer simulations of nanowires between a heat source and a heat sink have shown that in the middle of such wires the temperature…
Recent experimental and theoretical results on intrinsic superconductivity in ropes of single-wall carbon nanotubes are reviewed and compared. We find strong experimental evidence for superconductivity when the distance between the normal…
The search for materials with large thermopower is of great practical interest. Dirac and Weyl semimetals have recently proven to exhibit superior thermoelectric properties, particularly when subjected to a quantizing magnetic field. Here…
Materials with reduced dimensionality offer beneficial density-of-states (DOS) profiles for thermoelectric energy conversion, but can be impractical in realistic devices. Encouragingly, bulk high-symmetry materials can also exhibit similar…
The use of an asymmetric broadening in the transport distribution, a characteristic of resonant structures, is proposed as a route to engineer a decrease in electronic thermal conductivity thereby enhancing the electronic figure of merit in…