Theoretical exploration of mixed-anion antiperovskite semiconductors M3XN (M=Mg,Ca,Sr,Ba;X=P,As,Sb,Bi)

Yasuhide Mochizuki, Ha Jun Sung, Akira Takahashi, Yu Kumagai, Fumiyasu Oba

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

Antiperovskites have recently been attracting considerable attention because of their intriguing physical properties. We theoretically investigate polymorphism of mixed-anion antiperovskites M32+X3-N3-(M = Mg, Ca, Sr, Ba; X = P, As, Sb, Bi) using the seven representative crystal-structure prototypes of ABZ3 compounds. Stable crystal-structure exploration for four unreported compounds (Mg3PN,Sr3PN,Ba3PN, and Mg3BiN) is also performed using ab initio evolutionary crystal-structure-search and lattice-dynamics calculations, which have consistently identified antiperovskite phases as their ground states. As a result of crystal-structure exploration, the orthorhombic perovskite Pbnm phases of Mg3PN,Sr3PN, and Ba3PN are obtained, while the cubic perovskite Pm3¯m phase is stable in Mg3BiN. We show that the octahedral rotational distortions in M3PN and M3AsN reduce their Madelung energies, which is not common in conventional perovskites. Further, we estimate the ionic radii of anionic nitrogen N3- and pnictogen X3- to explain the chemical trends for the phase stability, lattice distortion amplitude, total energies, valence bandwidths, and band gaps of M3XN using the Goldschmidt tolerance factor. We also report the electronic structures of M3XN with and without the rotational distortions and spin-orbit coupling. The valence bands of Mg3XN are created mainly from p-p hybridization, whereas those of M3′XN(M′ = Ca, Sr, Ba) are constructed mainly from d-p hybridization. We then explain the mechanism of the band-gap changes owing to the rotational distortions and spin-orbit coupling. The effective masses for the relevant ground-state phases of M3XN are found to be comparable to preexisting compound semiconductors. Finally, we propose potential applications of earth-abundant semiconductors Mg3PN and Sr3PN as light absorbers and emitters utilizing their direct-type band structures and high optical absorption coefficients. The present study provides a clear picture and recipe for the understanding and design of mixed-anion antiperovskites.

Original languageEnglish
Article number044601
JournalPhysical Review Materials
Volume4
Issue number4
DOIs
Publication statusPublished - 2020 Apr
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)

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