Approaches to Estimate the Magnitude of Phonon Scattering via Point Defects in Mo(Se1-xTex)2 Thermoelectric Alloys

You Jong Lee, Sang Il Kim, Seong Mee Hwang, Jeong Yeon Kim, Won Seon Seo, Hyun Sik Kim

Research output: Contribution to journalArticlepeer-review

Abstract

One of the most popular routes used to improve the thermoelectric performance of materials is to suppress their lattice thermal conductivities. Thermoelectric performance is characterized by a figure-of-merit zT, which is defined as σS2T/(κe + κl), where the σ, S, T, κe, and κl are the electrical conductivity, Seebeck coefficient, temperature (in Kelvin), electronic thermal conductivity, and the lattice thermal conductivity, respectively. Among the variables in zT, the κl is the only variable that is independent of all other variables. In other words, reduction in κl guarantees zT improvement. Therefore, several different strategies to decrease κl have been introduced and implemented. Among the many κl reduction strategies, introducing point defects in the material by forming an alloy is particularly effective. Here, phonon scattering due to point defects in Mo(Se1-xTex)2 (x = 0.0, 0.25, 0.50, 0.75, 1.0) was studied using both the Debye-Callaway (DC) model and Callaway-von Baeyer (CvB) model. The advantages and disadvantages of using DC or CvB models are thoroughly discussed. When analyzing the effect of phonon scattering due to point defects, the CvB model is simpler and gives more information about the details of phonon scattering.

Original languageEnglish
Pages (from-to)38-45
Number of pages8
JournalJournal of Korean Institute of Metals and Materials
Volume61
Issue number1
DOIs
StatePublished - Jan 2023

Keywords

  • callaway-von baeyer model
  • debye-callaway model
  • hermoelectric
  • lattice thermal conductivity
  • point defect

Fingerprint

Dive into the research topics of 'Approaches to Estimate the Magnitude of Phonon Scattering via Point Defects in Mo(Se1-xTex)2 Thermoelectric Alloys'. Together they form a unique fingerprint.

Cite this