Enhancement of thermoelectric efficiency in a double-quantum-dot molecular junction

Abstract

We propose a high-efficiency molecular junction consisting of a double-coupled-quantum-dot molecule sandwiched between two metallic electrodes. ZT can be enhanced in the Fano-line-shape regime, and it is sensitive to the magnetic flux threading through the double-coupled-quantum-dot molecular junction. This is mainly due to the local density of states in the Fano-line-shape regime may become narrower, and an abrupt changing in the conductance (transmission) spectrum is developed. We find the value of ZT can exceed 1 at room temperature by controlling the chemical potential or magnetic flux. So our results indicate such a molecular junction may be used to the solid-state thermoelectric energy-conversion device at room temperature.

Enhancement of Thermoelectric Effects in a Single Molecular Magnet due to Resonance Tunnelling

“…Specially, in single-molecule devices the high figure of merit (ZT 1) can be obtained by tuning Fano resonances near the Fermi energy [17]. The similar conclusions have been confirmed in double quantum dot molecular junction [18,19]. Since the thermoelectric effect in molecular junction can reveal transport mechanisms through the molecular junction [20] and the experiments have demonstrated the capability of measuring the Seebeck coefficient in atomic and molecular junctions [21,Resonance Tunnelling 22], the thermoelectric effect of the single molecule devices attracts much interest [5,17,[23][24][25][26][27].…”

Spin-dependent thermoelectric effects in a strongly correlated double quantum dot

“…Existence of such molecular states has been verified experimentally for semiconductor double quantum dots and carbon nanotube quantum dots and has been shown to greatly influence transport through those multilevel systems in different coupling regimes [17][18][19][20]. Furthermore, it has been predicted that the electrons propagating coherently through the dots can interfere both constructively and destructively leading to Dicke [21][22][23] or Fano effects [24][25][26] resulting in enhanced thermoelectric response [27][28][29][30][31][32][33][34].…”

Length enhancement of thermoelectric effects in DNA duplex chains due to quantum interferences

“…The Seebeck coefficient indicates the voltage difference created by unit temperature difference between the electrodes and can be obtained by [31] Sðl; TÞ ¼ À lim…”

“…A large value of ZT might result from a large value of S, a large r, or a low thermal conductance (j el þ j ph ). The electron thermal conductance is expressed as: [31] j el ðl; TÞ ¼…”