Detailed Information

Cited 0 time in webofscience Cited 0 time in scopus
Metadata Downloads

Impact of Fermi Surface Shape Engineering on Calculated Electronic Transport Properties of Bi-Sb-Te

Authors
Kim, Sang-ilLim, Jong-ChanYang, HeesunKim, Hyun-Sik
Issue Date
Jan-2021
Publisher
KOREAN INST METALS MATERIALS
Keywords
Band mass of a single Fermi pocket; Conductivity effective mass; Non-parabolicity factor; Power factor; Thermoelectric
Citation
KOREAN JOURNAL OF METALS AND MATERIALS, v.59, no.1, pp.54 - 60
Journal Title
KOREAN JOURNAL OF METALS AND MATERIALS
Volume
59
Number
1
Start Page
54
End Page
60
URI
https://scholarworks.bwise.kr/hongik/handle/2020.sw.hongik/15654
DOI
10.3365/KJMM.2021.59.1.54
ISSN
1738-8228
Abstract
Using thermoelectric refrigerators can address climate change because they do not utilize harmful greenhouse gases as refrigerants. To compete with current vapor compression cycle refrigerators, the thermoelectric performance of materials needs to be improved. However, improving thermoelectric performance is challenging because of the trade-off relationship between the Seebeck coefficient and electrical conductivity. Here, we demonstrate that decreasing conductivity effective mass by engineering the shape of the Fermi surface pocket (non-parabolicity factor) can decouple electrical conductivity from the Seebeck coefficient. The effect of engineering the non-parabolicity factor was shown by calculating the electronic transport properties of a state-of-the-art Bi-Sb-Te ingot via two-band model with varying non-parabolicity. The power factor (the product of the Seebeck coefficient squared and electrical conductivity) was calculated to be improved because of enhanced electrical conductivity, with an approximately constant Seebeck coefficient, using a non-parabolicity factor other than unity. Engineering the non-parabolicity factor to achieve lighter conductivity effective mass can improve the electronic transport properties of thermoelectric materials because it only improves electrical conductivity without decreasing the Seebeck coefficient (which is directly proportional to the band mass of a single Fermi surface pocket and not to the conductivity effective mass). Theoretically, it is demonstrated that a thermoelectric figure-of-merit zT higher than 1.3 can be achieved with a Bi-Sb-Te ingot if the non-parabolicity factor is engineered to be 0.2. Engineering the non-parabolicity factor is another effective band engineering approach, similar to band convergence, to achieve an effective improvement in power factor.
Files in This Item
There are no files associated with this item.
Appears in
Collections
Graduate School > Materials Science and Engineering > 1. Journal Articles

qrcode

Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.

Related Researcher

Researcher Yang, Hee sun photo

Yang, Hee sun
Graduate School (Department of Materials Science and Engineering)
Read more

Altmetrics

Total Views & Downloads

BROWSE