Structure impact on the thermal and electronic properties of bismuth telluride by ab-initio and molecular dynamics calculations
Résumé
We use molecular dynamics and ab-initio methods to predict the thermal and electronic properties of new materials with high figures of merit. The simulated systems are bulk bismuth tellurides with antisite and vacancy defects. Optimizations of the materials under investigation are performed by the SIESTA code for subsequent calculations of force constants, electronic properties, and Seebeck coefficients. The prediction of the thermal conductivity is made by Non-Equilibrium Molecular Dynamics (NEMD) using the LAMMPS code. The thermal conductivity of bulk bismuth telluride with different stoichiometry and with a number of substitution defects is calculated. We have found that the thermal conductivity can be decreased by 60% by introducing vacancy defects. The calculated thermal conductivities for the different structures are compared with the available experimental and theoretical results. © Published under licence by IOP Publishing Ltd.
Mots clés
Bismuth
Bismuth compounds
Calculations
Defects
Electronic properties
Molecular dynamics
Tellurium compounds
Vacancies
Ab initio method
Bismuth telluride
Different structure
Figures of merits
Force constants
Molecular dynamics calculation
Non equilibrium molecular dynamic (NEMD)
Simulated system
Thermal conductivity