The Defect Tolerance of Chalcogenide Perovskites BaZrS<sub>3</sub> and Ba<sub>3</sub>Zr<sub>2</sub>S<sub>7</sub>

ORAL

Abstract

Chalcogenide perovskites (CPs), such as BaZrS3, have been proposed as defect-tolerant materials, which maintain the electronic properties of their pristine form even in the presence of defects, with desirable characteristics such as large absorption coefficients, and long recombination lifetime for application as solar cells and optoelectronic devices. A systematic investigation of the defect tolerance of such perovskites is critical to develop a full understanding of their potential. We have used BaZrS3 and Ba3Zr2S7 as prototypical CPs and investigated their defect tolerance to intrinsic point defects using a combination of density-functional-theory calculations, spectroscopic and transport measurements. Our calculation indicates that most defects lead to shallow levels. However, we find that the sulfur vacancies have low formation energy and lead to a deep transition level that is spatially localized to act as non-radiative recombination center in BaZrS3. Our work demonstrates that control over the chalcogen stoichiometry is critical to improve the performance of CPs. We also find that sulfur vacancies act as shallow-level defects in Ba3Zr2S7, a derivative of BaZrS3 with layered structure, making Ba3Zr2S7 a promising alternative for semiconducting applications.

*NSF DMR-1806147.

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Presenters

  • Jiang Luo

    • Department of Chemistry, Washington University in St. Louis

Authors

  • Jiang Luo

    • Department of Chemistry, Washington University in St. Louis

  • Boyang Zhao

    • University of Southern California
    • Mork Family Department of Chemical Engineering and Materials Science, University of Southern California

  • ZHAOHAN ZHANG

    • Institute of Materials Science & Engineering, Washington University in St. Louis
    • Institute of Materials Science & Engineering, Department of Mechanical Engineering & Materials Science, Washington University in St. Louis
    • Institute of Materials Science & Engineering, Washington University, St. Louis

  • Huandong Chen

    • Mork Family Department of Chemical Engineering and Materials Science, University of Southern California

  • Arashdeep Thind

    • Institute of Materials Science & Engineering, Washington University in St. Louis
    • Institute of Materials Science and Engineering, Washington University in St. Louis
    • Institute of Materials Science & Engineering, Washington University, St. Louis

  • Steven Hartman

    • Institute of Materials Science & Engineering, Washington University in St. Louis
    • Materials Science and Technology Division, Los Alamos National Laboratory
    • Institute of Materials Science & Engineering, Washington University, St. Louis

  • Bryce Sadtler

    • Department of Chemistry, Washington University in St. Louis

  • Jayakanth Ravichandran

    • University of Southern California
    • Mork Family Department of Chemical Engineering and Materials Science, University of Southern California
    • University of Southern California, Los Angeles

  • Rohan Mishra

    • Department of Mechanical Engineering & Materials Science, Washington University in St. Louis
    • Institute of Materials Science & Engineering, Department of Mechanical Engineering & Materials Science, Washington University in St. Louis
    • Washington University, St. Louis
    • Institute of Materials Science and Engineering, Washington University in St. Louis
    • Institute of Materials Science & Engineering, Washington University, St. Louis