Non-linear effects and thermoelectric efficiency of quantum dot-based single-electron transistors

Abstract

By means of advanced numerical simulation, the thermoelectric properties of a Si-quantum dot-based single-electron transistor operating in sequential tunneling regime are investigated in terms of figure of merit, efficiency and power. By taking into account the phonon-induced collisional broadening of energy levels in the quantum dot, both heat and electrical currents are computed in a voltage range beyond the linear response. Using our homemade code consisting in a 3D Poisson-Schrödinger solver and the resolution of the Master equation, the Seebeck coefficient at low bias voltage appears to be material independent and nearly independent on the level broadening, which makes this device promising for metrology applications as a nanoscale standard of Seebeck coefficient. Besides, at higher voltage bias, the non-linear characteristics of the heat current are shown to be related to the multi-level effects. Finally, when considering only the electronic contribution to the thermal conductance, the single-electron transistor operating in generator regime is shown to exhibit very good efficiency at maximum power.

Constructed Ge Quantum Dots and Sn Precipitate SiGeSn Hybrid Film with High Thermoelectric Performance at Low Temperature Region

“…Recently, Talbo et al [ 23 ] reported that in quantum dot‐based single‐electron transistors, the theoretically calculated ZT can go up to 200. Urban predicted that quantum dot hybrid arrays may lead to advanced TE performance and silicon‐based TE devices could have a prominent role in this possible future with a moderate ZT .…”

Nonmonotonic thermoelectric currents and energy harvesting in interacting double quantum dots

“…For instance, in molecular junctions, the thermoelectric voltage and thermopower can distinguish between different transport mechanisms [7][8][9] . Thermopower in quantum dots was studied over two decades ago, both theoretically and experimentally [10][11][12] , with recent resurging interest focusing on role of interactions and non-linearity on thermoelectric efficiency [13][14][15][16][17][18][19][20][21][22] (see review in, e.g., Ref. 23).…”

Thermal transport controlled by intra- and inter-dot Coulomb interactions in sequential and cotunneling serially-coupled double quantum dots

“…The drag effect is a phenomenon, where a current flowing in a so-called drive conductor induces a voltage across a nearby drag conductor via the Coulomb interaction [16]. It has been shown by experimental and theoretical arguments that the cotunneling process is essential to obtain a correct qualitative understanding of the transport and drag properties in a Coulomb-coupled double quantum dot [17,18]. In addition, a dynamical signature of the Coulomb-blockade is seen, where the excited states are more active than the ground state even at a low electron number [19].…”