Toward high-performance nanostructured thermoelectric materials: the progress of bottom-up solution chemistry approaches

Abstract

Significant research effort has recently gone into the synthesis of thermoelectric nanomaterials through different chemical approaches since nanomaterials chemistry became a promising strategy for improving thermoelectric performance. Different thermoelectric nanocrystals, especially PbTe, Bi 2 Te 3 and CoSb 3 , with various compositions and morphologies have been successfully prepared by solvo/ hydrothermal, electrochemical, and ligand-based synthesis methods. Such nanoscale materials show not only substantial reduction in thermal conductivity due to increased phonon scattering at nanoscale grain boundaries and lower densities of phonon states but possibly also an enhancement in thermopower due to electronic quantum size effects. More recently, the notoriously low power factors of thermoelectric nanomaterials prepared by wet chemistry have been significantly improved by using an increasingly cross-disciplinary approach towards the bottom-up synthesis that combines expertise from chemistry, physics, and materials engineering. In this review, we discuss the recent progress and current challenges of preparing thermoelectric nanomaterials with solution-based chemistry approaches.

Boundary Engineering for the Thermoelectric Performance of Bulk Alloys Based on Bismuth Telluride

“…[129][130][131][132][133][134][135][136][137][138][139] Briefly,w ei ntroducet he processing technologies that can be used to synthesize nanoscale Bi 2 Te 3 -based alloys, which include bottom-up [73][74][75][76][77][78][79][80][81][82][83] (the solvothermalm ethod and wet-chemical reaction) and top-down [64,66,[69][70][71] (high-energyB Ma nd MS) processes. [129][130][131][132][133][134][135][136][137][138][139] Briefly,w ei ntroducet he processing technologies that can be used to synthesize nanoscale Bi 2 Te 3 -based alloys, which include bottom-up [73][74][75][76][77][78][79][80][81]…”

“…Several nonconventional nanostructuring approaches for boundary engineering have allowedn otable successesw ith regard to the enhancement of TE performance levels. [129][130][131][132][133][134][135][136][137][138][139] Briefly,w ei ntroducet he processing technologies that can be used to synthesize nanoscale Bi 2 Te 3 -based alloys, which include bottom-up [73][74][75][76][77][78][79][80][81][82][83] (the solvothermalm ethod and wet-chemical reaction) and top-down [64,66,[69][70][71] (high-energyB Ma nd MS) processes. Our new technologiesd eveloped for boundary engineering are also presented.…”

Multifunctional Copper‐Based Quaternary Chalcogenide Semiconductors Toward State‐of‐the‐Art Energy Applications

“…Thermoelectric technology is based on the principle of conversion of heat energy into electrical energy using solid state devices called thermoelectric generators . Figure a depicts the schematic representation of a thermoelectric generator.…”

“…At nanoscale regime, the quantities S, σ and κ can be varied quasi‐independently as a new length variable is added . Nanocrystalline materials with interesting scattering mechanism at nanoscale grain boundaries are expected to have lower lattice thermal conductivity and possible quantum effects could enhance the power factor ,,,. Large number of grain boundaries in nanomaterials leads to large phonon scattering that is helpful in scattering in long‐ range phonons as shown in Figure b.…”

Enhanced thermoelectric properties of hybridized conducting aerogels based on carbon nanotubes and pyrolyzed resorcinol–formaldehyde resin

“…During the last two decades, a number of methods and structures (e.g., superlattices [6], nanostructure [5,[7][8][9][10], low-dimensional structures [11,12], and phonon-glass/electron-crystal (PGEC) [13] have been explored to decouple a, k and s, and achieve high ZT values. Although these methods allow the independent regulation of the three parameters, they are too complicated and cannot be scaled up.…”