Pnictogen-based zintl Compounds: Unlocking the electronic, optical, and thermoelectric potential of Mg2ZnX2 (X = P, as, sb)

Abstract

This paper presents a comprehensive first-principles investigation into the electronic, optical, mechanical, and thermoelectric properties of Pnictogen-based Zintl compounds Mg₂ZnX₂ (X = P, As, Sb). By employing the GGA-PBEsol approach and refining through the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential, it is revealed that Mg₂ZnP₂ and Mg₂ZnAs₂ exhibit direct band gaps, while Mg₂ZnSb₂ has an indirect band gap, with tunable values of (1.47, 0.99, and 0.26) eV, respectively. These insights open new possibilities for precise electronic tailoring. The structure stability of Mg₂ZnX₂ (X = P, As, Sb) were conformed to performed phonon dispersion. Our elastic property analysis confirms the mechanical stability and ductility of all compounds, positioning them as robust candidates for practical applications. Furthermore, optical properties highlight their potential in next-generation optical devices. Thermoelectric performance, evaluated through the BoltzTraP code, reveals an impressive ZT value of 0.83 at 1000 K for Mg₂ZnP₂, marking it as highly efficient for thermoelectric applications. The multifunctionality and high potential of Mg₂ZnX₂ compounds make them exciting prospects for advanced optoelectronic and thermoelectric devices.