TAILIEUCHUNG - Electronic thermal conductivity and thermoelectric performance of n-type PbBi4Te7

In this work, in the framework of density functional theory, we study the electronic thermal conductivity of the compound by employing the solution of Boltzmann Transport Equation in a constant relaxationtime approximation. The results show that the electronic thermal conductivity drastically increases with the increase of temperature and carrier concentration which have a detrimental effect on the thermoelectric performance. | VNU Journal of Science Mathematics Physics Vol. 36 No. 3 2020 74-80 Original Article Electronic Thermal Conductivity and Thermoelectric Performance of n-type PbBi4Te7 Tran Van Quang Department of Physics University of Transport and Communications No. 3 Cau Giay Lang Thuong Dong Da Hanoi Vietnam Received 25 February 2020 Revised 01 April 2020 Accepted 15 May 2020 Abstract Bismuth telluride and its related compounds are the state-of-the-art thermoelectric materials operating at room temperature. Bismuth telluride with Pb substituted PbBi4Te7 has been found to be a new quasi-binary compound with an impressive high power factor. In this work in the framework of density functional theory we study the electronic thermal conductivity of the compound by employing the solution of Boltzmann Transport Equation in a constant relaxation- time approximation. The results show that the electronic thermal conductivity drastically increases with the increase of temperature and carrier concentration which have a detrimental effect on the thermoelectric performance. At a particular temperature the competition between the thermal conductivity the Seebeck coefficient and the electrical conductivity limits the thermoelectric figure of merit ZT. The maximum ZT value of about occurs at 520 K and at the carrier concentration of 1019cm-3 for n-type doping. This suggests that to maximize the thermoelectric performance of the compound the carrier concentration must be carefully controlled and optimized whereas the best operating temperature is around 500 K. Keywords Electronic thermal conductivity thermoelectric material PbBi4Te7 first-principles calculation. 1. Introduction Nowadays the demand for new energy resources due to environmental impacts and exhausted fossil fuels is increasing. One of the potential methods is the scavenging of waste heat with thermoelectric modules which are able to convert unused waste heat directly into electricity silently reliably and ________ .

• Toán học
• Electronic thermal conductivity
• Thermoelectric material
• First principlescalculation
• The electrical conductivity
• The thermoelectric performance
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