Analyzing Particle Size Effects in ZnS:Cu using X-ray Absorption Spectroscopy

ORAL

Abstract

We report XAS measurements on ZnS:Cu,Mn phosphor materials of various particle sizes, 1-25$\mu$m. These materials exhibit electroluminescence (EL) at AC voltages of order 100V for $\sim$25$\mu$m particles, but only from small points associated with CuS nanoprecipitates (which form along the 111 plane in ZnS); here the local electric fields are enhanced by a factor of about 100. To enable lower-voltage applications, it is desirable to make smaller particles so devices can be thinner. We investigated the local structure for smaller particles produced by mill-grinding to determine why grinding leads to reduced AC EL. The K-edge EXAFS data show a decreased Cu-S first peak amplitude for the ground particle samples, but little change for Mn-S or Zn-S peaks. The XANES data show a large change in the structure of the Cu K-edge for smaller particles but not for either the host Zn or Mn dopant edges. Clearly grinding affects the environment about Cu, in the CuS precipitates, much more than the ZnS host lattice. Possibly the ZnS particles fracture preferentially through the CuS precipitates or the ZnS particles are partially sheared along the 111 plane.

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Authors

  • Scott Medling

    UC Santa Cruz

  • Joshua Lusk

    University of New Mexico, Gallup Campus, Sciprint.org, Institute of Gravitation and Cosmology, Moscow, Russia, CSU Long Beach, California State University - East Bay, LLNL, UC Santa Cruz, University of California, Berkeley, Loma Linda Medical University, Northern Illinois University, Santa Cruz Institute for Particle Physics, Dr, Pr, California State University Long Beach, California Polytechnic State University, Department of Physics, California State University, Fresno, NPS, UC-Davis, University of California-Davis, University of California Riverside, Rutgers University, Pomona College, Department of Physics, Imperial College London, Materials Research Laboratory, UC Santa Barbara, Naval Postgraduate School, Whittier College, Cardiff University, Cardiff, Wales - Cardiff School of Biosciences, University of California, Davis - Electrical and Computer Engineering, University of California, Davis - Neurosurgery, Materials Department, University of California, Santa Barbara, CA 93106-5050, Queen's University, Belfast, Rutherford Appleton Laboratory, Technical University of Darmstadt, University of York, University of California, Los Angeles, Kohat University of Science and Technology, Lawrence Livermore National Laboratory, Imperial College, The Blackett Laboratory, University of Strathclyde, University of Oxford, UC Berkeley, UC Berkeley, SLAC, Gesellschaft f\"ur Schwerionenforschung GSI, University of Washington, Seattle, LLNL and XIA LLC, University of Graz, University of California, Davis, Naval Surface Warfare Center-Indian Head Division

  • Joshua Lusk

    University of New Mexico, Gallup Campus, Sciprint.org, Institute of Gravitation and Cosmology, Moscow, Russia, CSU Long Beach, California State University - East Bay, LLNL, UC Santa Cruz, University of California, Berkeley, Loma Linda Medical University, Northern Illinois University, Santa Cruz Institute for Particle Physics, Dr, Pr, California State University Long Beach, California Polytechnic State University, Department of Physics, California State University, Fresno, NPS, UC-Davis, University of California-Davis, University of California Riverside, Rutgers University, Pomona College, Department of Physics, Imperial College London, Materials Research Laboratory, UC Santa Barbara, Naval Postgraduate School, Whittier College, Cardiff University, Cardiff, Wales - Cardiff School of Biosciences, University of California, Davis - Electrical and Computer Engineering, University of California, Davis - Neurosurgery, Materials Department, University of California, Santa Barbara, CA 93106-5050, Queen's University, Belfast, Rutherford Appleton Laboratory, Technical University of Darmstadt, University of York, University of California, Los Angeles, Kohat University of Science and Technology, Lawrence Livermore National Laboratory, Imperial College, The Blackett Laboratory, University of Strathclyde, University of Oxford, UC Berkeley, UC Berkeley, SLAC, Gesellschaft f\"ur Schwerionenforschung GSI, University of Washington, Seattle, LLNL and XIA LLC, University of Graz, University of California, Davis, Naval Surface Warfare Center-Indian Head Division

  • Joshua Lusk

    University of New Mexico, Gallup Campus, Sciprint.org, Institute of Gravitation and Cosmology, Moscow, Russia, CSU Long Beach, California State University - East Bay, LLNL, UC Santa Cruz, University of California, Berkeley, Loma Linda Medical University, Northern Illinois University, Santa Cruz Institute for Particle Physics, Dr, Pr, California State University Long Beach, California Polytechnic State University, Department of Physics, California State University, Fresno, NPS, UC-Davis, University of California-Davis, University of California Riverside, Rutgers University, Pomona College, Department of Physics, Imperial College London, Materials Research Laboratory, UC Santa Barbara, Naval Postgraduate School, Whittier College, Cardiff University, Cardiff, Wales - Cardiff School of Biosciences, University of California, Davis - Electrical and Computer Engineering, University of California, Davis - Neurosurgery, Materials Department, University of California, Santa Barbara, CA 93106-5050, Queen's University, Belfast, Rutherford Appleton Laboratory, Technical University of Darmstadt, University of York, University of California, Los Angeles, Kohat University of Science and Technology, Lawrence Livermore National Laboratory, Imperial College, The Blackett Laboratory, University of Strathclyde, University of Oxford, UC Berkeley, UC Berkeley, SLAC, Gesellschaft f\"ur Schwerionenforschung GSI, University of Washington, Seattle, LLNL and XIA LLC, University of Graz, University of California, Davis, Naval Surface Warfare Center-Indian Head Division

  • Joshua Lusk

    University of New Mexico, Gallup Campus, Sciprint.org, Institute of Gravitation and Cosmology, Moscow, Russia, CSU Long Beach, California State University - East Bay, LLNL, UC Santa Cruz, University of California, Berkeley, Loma Linda Medical University, Northern Illinois University, Santa Cruz Institute for Particle Physics, Dr, Pr, California State University Long Beach, California Polytechnic State University, Department of Physics, California State University, Fresno, NPS, UC-Davis, University of California-Davis, University of California Riverside, Rutgers University, Pomona College, Department of Physics, Imperial College London, Materials Research Laboratory, UC Santa Barbara, Naval Postgraduate School, Whittier College, Cardiff University, Cardiff, Wales - Cardiff School of Biosciences, University of California, Davis - Electrical and Computer Engineering, University of California, Davis - Neurosurgery, Materials Department, University of California, Santa Barbara, CA 93106-5050, Queen's University, Belfast, Rutherford Appleton Laboratory, Technical University of Darmstadt, University of York, University of California, Los Angeles, Kohat University of Science and Technology, Lawrence Livermore National Laboratory, Imperial College, The Blackett Laboratory, University of Strathclyde, University of Oxford, UC Berkeley, UC Berkeley, SLAC, Gesellschaft f\"ur Schwerionenforschung GSI, University of Washington, Seattle, LLNL and XIA LLC, University of Graz, University of California, Davis, Naval Surface Warfare Center-Indian Head Division

  • Joshua Lusk

    University of New Mexico, Gallup Campus, Sciprint.org, Institute of Gravitation and Cosmology, Moscow, Russia, CSU Long Beach, California State University - East Bay, LLNL, UC Santa Cruz, University of California, Berkeley, Loma Linda Medical University, Northern Illinois University, Santa Cruz Institute for Particle Physics, Dr, Pr, California State University Long Beach, California Polytechnic State University, Department of Physics, California State University, Fresno, NPS, UC-Davis, University of California-Davis, University of California Riverside, Rutgers University, Pomona College, Department of Physics, Imperial College London, Materials Research Laboratory, UC Santa Barbara, Naval Postgraduate School, Whittier College, Cardiff University, Cardiff, Wales - Cardiff School of Biosciences, University of California, Davis - Electrical and Computer Engineering, University of California, Davis - Neurosurgery, Materials Department, University of California, Santa Barbara, CA 93106-5050, Queen's University, Belfast, Rutherford Appleton Laboratory, Technical University of Darmstadt, University of York, University of California, Los Angeles, Kohat University of Science and Technology, Lawrence Livermore National Laboratory, Imperial College, The Blackett Laboratory, University of Strathclyde, University of Oxford, UC Berkeley, UC Berkeley, SLAC, Gesellschaft f\"ur Schwerionenforschung GSI, University of Washington, Seattle, LLNL and XIA LLC, University of Graz, University of California, Davis, Naval Surface Warfare Center-Indian Head Division