Mining Unexplored Chemistries for Phosphors for High-Color-Quality White-Light-Emitting Diodes

ORAL  · Invited

Abstract

There is a critical need for new earth-abundant phosphors to enable next-generation, highly efficient solid-state lighting. We report the discovery of Sr2LiAlO4, the first known Sr-Li-Al-O quaternary crystal, via a carefully-targeted data-driven structure prediction and screening effort using density functional theory calculations. Sr2LiAlO4 is predicted and experimentally confirmed to be a thermodynamically and thermally stable phosphor host that can be excited with near-UV/blue sources. The Eu2+ and Ce3+ activated Sr2LiAlO4 phosphors exhibit broad green-yellow/blue emissions, respectively, with excellent thermal quenching resistance of > 88% intensity at 150°C. A prototype phosphor-converted white LED utilizing Sr2LiAlO4-based phosphors yields an excellent color rendering index exceeding 90. Sr2LiAlO4 therefore exhibits great potential for industrial applications in low-cost, high-color-quality WLEDs.

*This work was supported by the National Science Foundation, Ceramics Program, under Grant No. 1411192.

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Presenters

  • Shyue Ping Ong

    • Department of NanoEngineering, University of California, San Diego

Authors

  • Shyue Ping Ong

    • Department of NanoEngineering, University of California, San Diego

  • Zhenbin Wang

    • Department of NanoEngineering, University of California, San Diego

  • Jungmin Ha

    • Materials Science and Engineering, University of California, San Diego

  • Yoon Hwa Kim

    • School of Materials Science and Engineering and Optoelectronics Convergence Research Center, Chonnam National University

  • Won-Bin Im

    • School of Materials Science and Engineering and Optoelectronics Convergence Research Center, Chonnam National University

  • Joanna McKittrick

    • Materials Science and Engineering, University of California, San Diego
    • Mechanical and Aerospace Engineering, UC San Diego