Structure, magnetic, opto-electronic and thermoelectric properties of A3In2As4 and A5In2As6 (A = Sr and Eu) Zintl phase compounds

Abstract

Structural, electronic, optical, thermoelectric and magnetic properties of A3In2As4 and A5In2As6 (A = Eu and Sr) Zintl phase compounds in orthorhombic (Pnma and Pbam) phases are examined using density functional theory. Structure properties are an agreement with the experiment. Magnetic properties disclose the Non-magnetic nature of Sr3In2As4 and Sr5In2As6 and anti-ferromagnetic nature of Eu3In2As4 and Eu5In2As6 compounds.Electronic properties of Sr3In2As4, Sr5In2As6 and Eu3In2As4, Eu5In2As6 shows that all these compounds have narrow direct bandgap semiconductors at ᴦ and M symmetry. Electrical conductivity also gives the information about the semiconducting characteristic of these compounds. These compounds show that reduction in bandgap occurs through the substitution of Sr by Eu while increasing by going from local density approximation to modified Becke-Johnson potential and further reduce by spin orbit coupling effect. The outcome demonstrates that all compounds are optically dynamic in the infrared region, anisotropic and obstruct ultraviolet waves so these compounds are capable to use as shield for ultraviolet radiation and can be used as paramount applicant for optoelectronic devices. Owing to low thermal conductivity, high Seebeck coefficient, power factor and Figure of merit ranges from 0.39 to 1.2 at 800 K indicating that all compounds are active aspirants for thermoelectric applications.