Decoding optoelectronic behavior in X$_3$BI$_3$ antiperovskite derivatives through many-body perturbation theory

TL;DR

This study uses advanced first-principles calculations to explore the optoelectronic, excitonic, and polaronic properties of X$_{3}$BI$_{3}$ antiperovskite derivatives, revealing their potential for efficient optoelectronic applications.

Contribution

It provides detailed theoretical insights into the structural and electronic properties of X$_{3}$BI$_{3}$ compounds using many-body perturbation theory, which were previously underexplored due to computational challenges.

Findings

All compounds have direct bandgaps suitable for light absorption.

Moderate exciton binding energies favor exciton dissociation.

Polaron mobilities up to 37.19 cm$^{2}$V$^{-1}$s$^{-1}$ were observed.

Abstract

Antiperovskite derivatives have emerged as promising candidates for optoelectronic applications. However, due to the significant computational cost, their excitonic and polaronic properties remain underexplored despite being critical for optoelectronic performance. Here, we present the structural, electronic, optical, excitonic, and polaronic properties of a series of antiperovskite derivatives with the chemical formula X$_{3}$BI$_{3}$ (X = Ca, Sr; B = P, As, Sb, Bi) using state-of-the-art first-principles calculations. All the compounds exhibit direct bandgaps with G$_{0}$W$_{0}$@PBE bandgap ranging from 2.42 to 3.02 eV, optimal for efficient light absorption with minimal energy loss. Exciton binding energies (0.258-0.318 eV) indicate moderate Coulomb attraction, favoring exciton dissociation. Employing the Feynman polaron model, we established the polaronic properties, where weak to intermediate carrier-phonon coupling was observed, with polaron mobilities reaching values up to 37.19 cm$^{2}$V$^{-1}$s$^{-1}$. These properties establish X$_{3}$BI$_{3}$ materials as viable candidates for next-generation optoelectronic devices.