Complex chalcogenides as highly-polarizable semiconductors

ORAL

Abstract

Ternary sulfides and selenides in the distorted-perovskite and related structures (“complex chalcogenides”) are predicted to be semiconductors with band gap in the visible-to-infrared, and may be useful for optical, electronic, and energy conversion technologies. The crystal structures familiar to complex oxides, together with larger chalcogenide anions, suggest that complex chalcogenides will be highly polarizable semiconductors.

We will report theoretical and experimental progress towards establishing the fundamentals of highly-polarizable complex chalcogenide semiconductors. We use computational thermodynamics to predict the phase diagrams for select materials, highlighting windows of equilibrium between solid and vapor phases – relevant to growing films by molecular beam epitaxy (MBE). We then report on progress towards MBE growth of complex chalcogenide films, focusing on control of H2S and H2Se gas precursors. We will also report experimental results on complex chalcogenides in the Ba-Zr-S system, including time-resolved photoluminescence suggesting slow minority carrier recombination, and impedance spectroscopy providing evidence of highly-polarizable materials with band gap below 2 eV.

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Presenters

  • Rafael Jaramillo

    Massachusetts Institute of Technology, Department of Materials Science and Engineering, Massachusetts Institute of Technology

Authors

  • Stephen Filippone

    Massachusetts Institute of Technology

  • Shanyuan Niu

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

  • Kristopher Williams

    Department of Chemical Engineering, Massachusetts Institute of Technology, Massachusetts Institute of Technology

  • William A Tisdale

    Chemical Engineering, Massachusetts Institute of Technology (MIT), Department of Chemical Engineering, Massachusetts Institute of Technology, Massachusetts Institute of Technology

  • Yi-Yang Sun

    State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, CAS, Shanghai Institute of Ceramics, Chinese Academy of Sciences

  • Jayakanth Ravichandran

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

  • Rafael Jaramillo

    Massachusetts Institute of Technology, Department of Materials Science and Engineering, Massachusetts Institute of Technology