Designing and discovering a new family of semiconducting quaternary Heusler compounds based on the 18-electron rule

TL;DR

This paper introduces a new family of stable semiconducting quaternary Heusler compounds designed via high-throughput ab initio calculations based on the 18-electron rule, revealing materials with unique properties suitable for photovoltaic and thermoelectric applications.

Contribution

The study reports the discovery of 99 new stable semiconducting quaternary Heusler compounds using a novel design strategy based on the 18-electron rule and high-throughput calculations.

Findings

99 new semiconductors with band gaps 0.3-2.5 eV

Exhibit strong optical absorption and high Seebeck coefficient

Potential for photovoltaic and thermoelectric applications

Abstract

Intermetallic compounds with sizable band gaps are attractive for their unusual properties but rare. Here, we present a new family of stable semiconducting quaternary Heusler compounds, designed and discovered by means of high-throughput \textit{ab initio} calculations based on the 18-electron rule. The 99 new semiconductors reported here adopt the ordered quaternary Heusler structure with the prototype of LiMgSnPd (F$\bar{\mathbf{4}}$3m, No.\,216) and contain 18 valence electrons per formula unit. They are realized by filling the void in the half Heusler structure with a small and electropositive atom, i.e., lithium. These new stable quaternary Heusler semiconductors possess a range of band gaps from 0.3 to 2.5\,eV, and exhibit some unusual properties different from conventional semiconductors, such as strong optical absorption, giant dielectric screening, and high Seebeck coefficient, which suggest these semiconductors have potential applications as photovoltaic and thermoelectric materials. While this study opens up avenues for further exploration of this novel class of semiconducting quaternary Heuslers, the design strategy used herein is broadly applicable across a potentially wide array of chemistries to discover new stable materials.