Thermoelectric properties of rocksalt ZnO from first-principles calculations

Journal Article · 21 October 2015 · Journal of Applied Physics

DOI: https://doi.org/10.1063/1.4934522 · OSTI ID:1332447

Alvarado, Andrew ^[1]; Attapattu, Jeevake ^[2]; Zhang, Yi ^[2]; Chen, Changfeng ^[2]

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1. Univ. of Nevada, Las Vegas, NV (United States); UNLV
2. Univ. of Nevada, Las Vegas, NV (United States)

Zinc oxide (ZnO) undergoes a pressure-induced structural transition from its normal ambient-pressure wurtzite (WZ) phase to a rocksalt (RS) phase around 10 GPa. A recent experiment shows that the high-pressure RS ZnO phase can be recovered and stabilized at ambient conditions, which raises exciting prospects of expanding the range of properties of ZnO. For a fundamental understanding of the RS ZnO phase, we have performed first-principles calculations to determine its electronic, phonon, and thermodynamic properties at high (20 GPa) and ambient (0 GPa) pressure. Furthermore, we have calculated its electrical and thermal transport properties, which allow an evaluation of its thermoelectric figure of merit ZT at different temperature and doping levels. Our calculations show that the ambient-pressure RS ZnO phase can reach ZT values of 0.25 to 0.3 under both n-type and p-type doping in a large temperature range of 400 K to 800 K, which is considerably lower than the temperature range of 1400 K to 1600 K where WZ ZnO reaches similar ZT values. Lastly, these results establish RS ZnO as a promising material for thermoelectric devices designed to operate at temperatures desirable for many heat recovery applications.

• Research Organization: Univ. of Nevada, Las Vegas, NV (United States)
• Sponsoring Organization: USDOE; USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: NA0001982
• OSTI ID: 1332447
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 16 Vol. 118; ISSN JAPIAU; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)Copyright Statement
• Country of Publication: United States
• Language: English