Title: A pencil-and-paper method for elucidating halide double perovskite band structures

Abstract

Halide double perovskites are an important emerging alternative to lead-halide perovskites in a variety of optoelectronic applications. Compared to ABX₃ single perovskites (A = monovalent cation, X = halide), A₂BB'X₆ double perovskites exhibit a wider array of compositions and electronic structures, promising finer control over physical and electronic properties through synthetic design. Yet, a clear understanding of how chemical composition dictates the electronic structures of this large family of materials is still lacking. In this work, we develop a qualitative Linear Combination of Atomic Orbitals (LCAO) model that describes the full range of band structures for double perovskites. Our simple model allows for a direct connection between the inherently local bonding between atoms in the double perovskite and the resulting delocalized bands of the solid. In particular, we show how bands in halide double perovskites originate from the molecular orbitals of metal–hexahalide coordination complexes and describe how these molecular orbitals vary within a band. Our findings provide both an enhanced understanding of known perovskite compositions and predictive power for identifying new compositions with targeted properties. We present a table, which permits the position of the conduction band minimum and valence band maximum in most double perovskites to be immediately determinedmore » from the frontier atomic orbitals of the B-site metals. Using purely qualitative arguments based on orbital symmetries and their relative energies, the direct/indirect nature of the bandgap of almost all halide double perovskites can thus be correctly predicted. We hope that this theory provides an intuitive understanding of halide double perovskite band structures and enables lessons from molecular chemistry to be applied to these extended solids.« less

Authors:

Slavney, Adam H.  ^[1];

• Search DOE PAGES for author "Slavney, Adam H."
• Search DOE PAGES for ORCID "0000-0002-2880-4081"

Connor, Bridget A.  ^[1];

• Search DOE PAGES for author "Connor, Bridget A."
• Search DOE PAGES for ORCID "0000-0002-0666-3943"

Leppert, Linn ^[2]; Karunadasa, Hemamala I.  ^[3]

• Search DOE PAGES for author "Karunadasa, Hemamala I."
• Search DOE PAGES for ORCID "0000-0003-4949-8068"

---

+ Show Author Affiliations

1. Department of Chemistry; Stanford University; Stanford; USA
2. Institute of Physics; University of Bayreuth; Bayreuth; Germany
3. Department of Chemistry; Stanford University; Stanford; USA; Stanford Institute for Materials and Energy Sciences

Publication Date:

Tue Jan 01 00:00:00 EST 2019

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1571834

Alternate Identifier(s):

OSTI ID: 1582224

Grant/Contract Number:  

AC02-76SF00515; DGE-114747

Resource Type:

Published Article

Journal Name:

Chemical Science

Additional Journal Information:

Journal Name: Chemical Science Journal Volume: 10 Journal Issue: 48; Journal ID: ISSN 2041-6520

Publisher:

Royal Society of Chemistry

Country of Publication:

United Kingdom

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY