Academic Journal

Ultralow lattice thermal conductivity of chalcogenide perovskite CaZrSe3 contributes to high thermoelectric figure of merit

التفاصيل البيبلوغرافية
العنوان: Ultralow lattice thermal conductivity of chalcogenide perovskite CaZrSe3 contributes to high thermoelectric figure of merit
المؤلفون: Osei-Agyemang, Eric, Adu, Challen Enninful, Balasubramanian, Ganesh
المساهمون: National Science Foundation
المصدر: npj Computational Materials ; volume 5, issue 1 ; ISSN 2057-3960
بيانات النشر: Springer Science and Business Media LLC
سنة النشر: 2019
الوصف: An emerging chalcogenide perovskite, CaZrSe 3 , holds promise for energy conversion applications given its notable optical and electrical properties. However, knowledge of its thermal properties is extremely important, e.g. for potential thermoelectric applications, and has not been previously reported in detail. In this work, we examine and explain the lattice thermal transport mechanisms in CaZrSe 3 using density functional theory and Boltzmann transport calculations. We find the mean relaxation time to be extremely short corroborating an enhanced phonon–phonon scattering that annihilates phonon modes, and lowers thermal conductivity. In addition, strong anharmonicity in the perovskite crystal represented by the Grüneisen parameter predictions, and low phonon number density for the acoustic modes, results in the lattice thermal conductivity to be limited to 1.17 W m −1 K −1 . The average phonon mean free path in the bulk CaZrSe 3 sample ( N → ∞) is 138.1 nm and nanostructuring CaZrSe 3 sample to ~10 nm diminishes the thermal conductivity to 0.23 W m −1 K −1 . We also find that p-type doping yields higher predictions of thermoelectric figure of merit than n-type doping, and values of ZT ~0.95–1 are found for hole concentrations in the range 10 16 –10 17 cm −3 and temperature between 600 and 700 K.
نوع الوثيقة: article in journal/newspaper
اللغة: English
DOI: 10.1038/s41524-019-0253-5
الاتاحة: http://dx.doi.org/10.1038/s41524-019-0253-5
https://www.nature.com/articles/s41524-019-0253-5.pdf
https://www.nature.com/articles/s41524-019-0253-5
Rights: https://creativecommons.org/licenses/by/4.0 ; https://creativecommons.org/licenses/by/4.0
رقم الانضمام: edsbas.1CDAC8D7
قاعدة البيانات: BASE
الوصف
DOI:10.1038/s41524-019-0253-5