High thermoelectric figure of merit of quantum dot array quantum wires

TL;DR

This paper proposes silicon-based quantum dot array nanowires with optimized topological distributions to achieve high thermoelectric efficiency, demonstrating potential for $ZT$ values exceeding 3 near room temperature.

Contribution

It introduces a novel design of quantum wires with tunable topological distributions to enhance thermoelectric performance, achieving high $ZT$ values in silicon QD arrays.

Findings

3D QD arrays can exhibit various topological distributions affecting thermoelectric properties.

1D topological distribution yields maximum power factor and $ZT$.

Silicon QD array nanowires with <20 nm diameter and 250 nm length can reach $ZT \,\ge 3$ near room temperature.

Abstract

How to design silicon-based quantum wires with figure of merit ($ZT$) larger than three is under hot pursuit due to the advantage of low cost and the availability of matured fabrication technique. Quantum wires consisting of finite three dimensional quantum dot (QD) arrays coupled to electrodes are proposed to realize high efficient thermoelectric devices with optimized power factors. The transmission coefficient of 3D QD arrays can exhibit 3D, 2D, 1D and 0D topological distribution functions by tailoring the interdot coupling strengths. Such topological effects on the thermoelectric properties are revealed. The 1D topological distribution function shows the maximum power factor and the best $ZT$ value. We have demonstrated that 3D silicon QD array nanowires with diameters below $20~nm$ and length $250~nm$ show high potential to achieve $ZT\ge 3$ near room temperature.