First‐principles study of optical and thermoelectric properties of Zn₃As₂ and ZnSb

Abstract

Thermoelectric materials have an important role in electronic chips due to their capability of heat and electricity interconversion. Here we investigated thermoelectric properties of Zn3As2 and ZnSb by using density functional theory combined with the Boltzmann transport equation. We evaluated the well‐known thermoelectric figure of merit (ZT) of both materials and found a maximum ZT of 0.09 and 0.27 for Zn3As2 and ZnSb at 200°C and 1000°C, respectively. While investigating the electronic properties, we found that Zn3As2 has a direct band‐gap at the Γ‐point of 1.01 eV, while ZnSb has an indirect bandgap of 0.65 eV. Both materials exhibited high optical absorption and reflectivity in the visible and UV regions, which suggest that these materials are beneficial in photovoltaic cells, along with thermoelectric applications.

Investigating Electronic, Optical, Thermodynamic, and Thermoelectric Properties of SrO and SrO2 Phases: A Density Functional Theory Approach

“…The electrical conductivity (σ), thermal conductivity (κ), and the Seebeck coefficient ( S ) can be expressed as a function of temperature ( T ), electron contribution (ε), and also the chemical potential (μ),as given by the following equations (value of ε varies between μ – k B T and μ + k B T ) σ = e 2 ∫ normalΞ i , k true[ prefix− ∂ F 0 ( T , ε , μ ) ∂ ε true] d ε k = italicek normalB σ ∫ normalΞ i , k true( ε − μ k B T true) true[ prefix− ∂ F 0 ( T , ε , μ ) ∂ ε true] d ε S = k B 2 T ∫ normalΞ i , k ( ε − μ k normalB T ) 2 true[ prefix− ∂ F 0 ( T , ε , μ ) ∂ ε true] d ε …”

“…The electrical conductivity (σ), thermal conductivity (κ), and the Seebeck coefficient ( S ) can be expressed as a function of temperature ( T ), electron contribution (ε), and also the chemical potential (μ),as given by the following equations (value of ε varies between μ – k B T and μ + k B T ) …”