Theoretical Insights into Inorganic Antiperovskite Nitrides (X$_3$NA; X = Mg, Sr, Ca, Ba; A = Sb, As): An Emerging Class of Materials for Photovoltaics

TL;DR

This study uses advanced theoretical methods to analyze inorganic antiperovskite nitrides, revealing their promising properties for photovoltaic applications due to favorable excitonic and charge transport characteristics.

Contribution

It provides a comprehensive theoretical analysis of excitonic and polaronic effects in X$_3$NA nitrides, highlighting their potential as efficient photovoltaic materials.

Findings

Low exciton binding energies in certain nitrides

Weak electron-phonon coupling enhances charge mobility

Significant ionic dielectric screening influences dielectric properties

Abstract

Antiperovskite nitrides are potential candidates for applications harvesting solar light. With a comprehensive state-of-the-art approach combining hybrid density-functional theory, many-body perturbation theory, the Wannier-Mott model, density-functional perturbation theory, and the Feynman polaron model, we explore excitonic and polaronic effects in X$_3$NA (X: Mg, Ca, Sr, Ba, A = Sb, As). For all of them, we uncover a significant influence of the ionic dielectric screening on the static dielectric constant. Small exciton binding energies, weak electron-phonon coupling, and high charge-carrier mobilities facilitate enhanced charge transport in Mg$_3$NSb, Sr$_3$NSb, and Ba$_3$NSb. Our results highlight the potential of these nitrides as optimal candidates for efficient photovoltaic absorbers.