Structure-Composition-Property Relationships in Antiperovskite Nitrides: Guiding a Rational Alloy Design

TL;DR

This study explores the structure-property relationships in antiperovskite nitrides, revealing a linear correlation between tolerance factor and physical properties, and designs a new alloy with promising photovoltaic characteristics.

Contribution

It establishes a novel structure-composition-property relationship in antiperovskite nitrides and demonstrates the first design of a promising alloy for photovoltaic applications.

Findings

Identified a linear relationship between tolerance factor and physical properties.

Designed a new alloy Mg3NAs0.5Bi0.5 with a quasi-direct band gap of 1.402 eV.

Compared antiperovskite nitrides with halide perovskites for future device applications.

Abstract

The alloy strategy through A- or X-site is a common method for experimental preparation of high-performance and stable lead-based perovskite solar cells. As one of the important candidates for lead-free and stable photovoltaic absorber, the inorganic antiperovskite family has recently been reported to exhibit excellent optoelectronic properties. However, the current reports on the design of antiperovskite alloys are rare. In this work, we investigated the previously overlooked electronic property (e.g., conduction band convergence), static dielectric constant, and exciton binding energy in inorganic antiperovskite nitrides by first-principles calculations. Then, we reveal a linear relationship between tolerance factor and various physical quantities. Guided by the established structure-composition-property relationship in six antiperovskite nitrides X3NA (X2+ = Mg2+, Ca2+, Sr2+; A3- = P3-, As3-, Sb3-, Bi3-), for the first time, we design a promising antiperovskite alloy Mg3NAs0.5Bi0.5 with the quasi-direct band gap of 1.402 eV. Finally, we make a comprehensive comparison between antiperovskite nitrides and conventional halide perovskites for pointing out the future direction for device applications.