Volume 11, Issue 1
First-Principles Investigations of Band Structure and Thermoelectric Properties of LiYN (Y = Be, Mg, Ca, Sr and Ba) Half- Heusler Compounds.
Abstract
Introduction: This work presents a first-principles investigation of the electronic structure and thermoelectric transport coefficients of LiYN(Y = Be, Mg, Ca, Sr, and Ba) half-Heusler(hH) compounds. Materials and Methods: Density Functional Theory calculation is carried out to investigate the thermoelectric properties of LiYN(Y = Be, Mg, Ca, Sr, and Ba) half-Heusler(hH) compounds. Aim The work determines the electronic and thermoelectric properties of these compounds. Results and Discussion: The bandgaps of these compounds range from 2.80eV for LiBeN to 1.01 for LiBaN, and the gap decreases down the group. The band structures of these compounds reveal mixtures of the flat band and parabolic bands. This mixture of bands enhances high-performance thermoelectric behaviours. The thermoelectric transport coefficients calculated in this work are electrical conductivity, thermal conductivity, Seebeck coefficient, power factor, and the dimensionless figure of merit. The figure of merit of LiCaN is 0.99 at the temperature of 1000K; this high figure of merit is due to the perfect flat band and parabolic band in these compounds’ conduction band. Conclusion: From the results obtained in this calculation, these compounds are high-performance thermoelectric candidates.