n-Type narrow band gap A3InAs3 (A = Sr and Eu) Zintl phase semiconductors for optoelectronic and thermoelectric applications

Abstract

Optoelectronic and thermoelectric properties of A3InAs3 (A = Sr and Eu) Zintl compounds are investigated using FP-LAPW method with LDA, GGA and mBJ potentials for Sr3InAs3 in addition with Hubbard (U) for Eu3InAs3 based on DFT. Electronic properties reveal that both the compounds are direct bandgap semiconductors and their semiconducting nature is also supported by electrical resistivity (conductivity). The direct bandgap value is ranging from 0.50 to 0.74 and is decreasing with the replacement of Sr by Eu. The results divulge that both the compounds are optically active in the infrared region and optically anisotropic in nature and can be used as a shield for ultraviolet radiation and potential candidate for optoelectronic devices. Negative value of -383 and -411 µV/K Seebeck coefficients suggest that electrons are the majority charge carriers. Low thermal conductivity, high Seebeck coefficient and high power factor indicating that A3InAs3 (A = Sr and Eu) are the potential matrix for thermoelectric application.