Phase transition enhanced thermoelectric performance for perovskites: The case of AgTaO3

• Published in: Current applied physics Vol. 48; pp. 84 - 89
• Main Authors: Wang, Zhijun, He, Zhijian, Lei, Chihou, Zou, Daifeng, Liu, Yunya
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2023
• Subjects: AgTaO3; Electronic structure; First-principles calculation; Phase transition; Thermoelectric; AgTaO3; Electronic structure; Thermoelectric; First-principles calculation; Phase transition
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2023.01.011

In general, perovskite materials, such as AgTaO3, can exhibit complex structural phase transitions when the temperature changes. Different phase structures may show distinct thermoelectric properties. However, the effects of phase transition on the thermoelectric performance of AgTaO3 have yet to be systematically investigated. Thus, in this work, the electronic structures and thermoelectric properties of the p-type AgTaO3 in various phase structures are investigated by utilizing first-principles calculations and semi-classical Boltzmann transport theory. The results show that the p-type AgTaO3 in the cubic phase shows a superior power factor because the cubic phase possesses a large Seebeck coefficient and intermediate electrical conductivity. The calculated thermoelectric performance is consistent with the predictions and explanations from the analyses of the electronic structures. When the p-type AgTaO3 is transformed from the tetragonal phase to the cubic phase, its power factor is tripled, suggesting that a suitable phase transition can improve the thermoelectric properties of perovskites. The power factor is enhanced by double times when the typical perovskite AgTaO3 transforms from tetragonal to cubic phase. [Display omitted] •The electronic structures of AgTaO3 in various phases were calculated.•The thermoelectric properties of p-type AgTaO3 in various phases were investigated.•The cubic p-type AgTaO3 shows a superior thermoelectric performance.•The power factor is enhanced by double times when AgTaO3 transforms from tetragonal to cubic phase.•An appropriate phase transition can enhance the thermoelectric performance of perovskites.