High Power Factor vs. High <i>zT</i>—A Review of Thermoelectric Materials for High-Temperature Application

Energy harvesting with thermoelectric materials has been investigated with increasing attention over recent decades. However, the vast number of various material classes makes it difficult to maintain an overview of the best candidates. Thus, we revitalize Ioffe plots as a useful tool for making the...

Full description

Bibliographic Details
Main Authors: Mario Wolf, Richard Hinterding, Armin Feldhoff
Format: Article
Language:English
Published: MDPI AG 2019-10-01
Series:Entropy
Subjects:
Online Access:https://www.mdpi.com/1099-4300/21/11/1058
Description
Summary:Energy harvesting with thermoelectric materials has been investigated with increasing attention over recent decades. However, the vast number of various material classes makes it difficult to maintain an overview of the best candidates. Thus, we revitalize Ioffe plots as a useful tool for making the thermoelectric properties of a material obvious and easily comparable. These plots enable us to consider not only the efficiency of the material by the figure of merit <i>zT</i> but also the power factor and entropy conductivity as separate parameters. This is especially important for high-temperature applications, where a critical look at the impact of the power factor and thermal conductivity is mandatory. Thus, this review focuses on material classes for high-temperature applications and emphasizes the best candidates within the material classes of oxides, oxyselenides, Zintl phases, half-Heusler compounds, and SiGe alloys. An overall comparison between these material classes with respect to either a high efficiency or a high power output is discussed.
ISSN:1099-4300