Transition-metal-nitride-based thin films as novel energy harvesting materials

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 4; no. 18; pp. 395 - 3914
• Main Authors: Eklund, Per, Kerdsongpanya, Sit, Alling, Björn
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 01.01.2016
• Subjects: Alloy systems; Chemistry; Energy harvesting; Nanostructure; Nitrides; Piezoelectricity; Rare earth metals; Thermoelectricity; Thin films
• ISSN: 2050-7526; 2050-7534; 2050-7534
• DOI: 10.1039/c5tc03891j

The last few years have seen a rise in the interest in early transition-metal and rare-earth nitrides, primarily based on ScN and CrN, for energy harvesting by thermoelectricity and piezoelectricity. This is because of a number of important advances, among those the discoveries of exceptionally high piezoelectric coupling coefficient in (Sc,Al)N alloys and of high thermoelectric power factors of ScN-based and CrN-based thin films. These materials also constitute well-defined model systems for investigating thermodynamics of mixing for alloying and nanostructural design for optimization of phase stability and band structure. These features have implications for and can be used for tailoring of thermoelectric and piezoelectric properties. In this highlight article, we review the ScN- and CrN-based transition-metal nitrides for thermoelectrics, and drawing parallels with piezoelectricity. We further discuss these materials as a models systems for general strategies for tailoring of thermoelectric properties by integrated theoretical-experimental approaches. We review experimental and theoretical research on ScN- and CrN-based transition-metal nitride materials for thermoelectrics, drawing parallels with piezoelectricity.