The Origin of Photoluminescence Center in 0D Cs<sub>4</sub>PbBr<sub>6</sub> Perovskite

ORAL

Abstract

0D perovskite Cs4PbBr6 has attracted considerable attention recently because of highly efficient green photoluminescence (PL) and highly debated opposing opinions on its photoluminescence origin: embedded CsPbBr3 nanocrystals versus intrinsic Br vacancy states. In this work, we provide sensitive but noninvasive methods to directly demonstrate that CsPbBr3 nanocrystals inclusions in Cs4PbBr6 are the dominant green PL source. We first use correlated Raman-PL method to identify the difference between emissive and non-emissive Cs4PbBr6 crystals and reveal the existence of CsPbBr3 nanocrystals in emissive Cs4PbBr6. We then measure the response of luminescence centers to hydrostatic pressure. The observations of red-shifting, diminishing, and eventual disappearance of both green emission and Raman under pressure exclude Br vacancies as possible luminescent centers. The resolution of this long-lasting controversy paves the way for further device applications of low dimensional perovskites, and our techniques are applied to other emerging materials.

–

Presenters

  • Zhaojun Qin

    • Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China

Authors

  • Zhaojun Qin

    • Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China

  • SHENYU DAI

    • College of Electronics & Information Engineering, Sichuan University
    • Sichuan University

  • Viktor G. Hadjiev

    • Texas Center for Superconductivity, University of Houston
    • University of Houston

  • Chong Wang

    • School of Materials Science and Engineering, Yunnan University
    • School of Materials and Energy, Yunnan University

  • Lixin Xie

    • Texas Center for Superconductivity, University of Houston

  • Yizhou Ni

    • Texas Center for Superconductivity, University of Houston

  • Chunzheng Wu

    • Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China

  • Guang Yang

    • Materials Science & Engineering, University of Houston

  • Shuo Chen

    • Texas Center for Superconductivity, University of Houston

  • Liangzi Deng

    • University of Houston
    • Texas Center for Superconductivity, University of Houston
    • Texas Center for Superconductivity & Physics Department at University of Houston
    • University of Houston, Texas Center for Superconductivity
    • Texas Center of Superconductivity and Physics Department at the University of Houston
    • TcSUH and Dept of Physics, University of Houston
    • Texas Center for Superconductivity and Department of Physics, University of Houston, Houston, TX 77204, USA
    • Texas Center for Superconductivity and Department of Physics, University of Houston

  • Qingkai Yu

    • Ingram School of Engineering, Texas State University

  • Guoying Feng

    • College of Electronics & Information Engineering, Sichuan University
    • Sichuan University

  • Zhiming M. Wang

    • Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China

  • Jiming Bao

    • Department of Electrical and Computer Engineering, University of Houston