Please use this identifier to cite or link to this item: http://buratest.brunel.ac.uk/handle/2438/8909
Title: Structure and morphology of ACEL ZnS:Cu,Cl phosphor powder etched by hydrochloric acid
Authors: Withnall, R
Silver, J
Ireland, TG
Fern, GR
Marsh, PJ
Keywords: Chlorine;Copper;Electroluminescence;Firing (materials);Materials preparation;Phosphors;Powders;Scanning electron microscopy;Solid state phase-transformations;Stacking faults;X-ray diffraction;Zinc compounds
Issue Date: 2009
Publisher: Electrochemical Society
Citation: Journal of the Electrochemical Society, 156(11), J326 - J332, 2009
Abstract: Despite many researches over the last half century, the mechanism of ac powder electroluminescence remains to be fully elucidated and, to this end, a better understanding of the relatively complex structure of alternate current electroluminescence (ACEL) phosphors is required. Consequently, the structure and morphology of ZnS:Cu,Cl phosphor powders have been investigated herein by means of scanning electron microscopy (SEM) on hydrochloric acid-etched samples and X-ray powder diffraction. The latter technique confirmed that, as a result of two-stage firing during their synthesis, the phosphors were converted from the high temperature hexagonal (wurtzite) structure to the low temperature cubic (sphalerite) polymorph having a high density of planar stacking faults. Optical microscopy revealed that the crystal habit of the phosphor had the appearance of the hexagonal polymorph, which can be explained by the sphalerite pseudomorphing of the earlier wurtzite after undergoing the hexagonal to cubic phase transformation during the synthesis. SEM micrographs of the hydrochloric-etched phosphor particles revealed etch pits, a high density of planar stacking faults along the cubic [111] axis, and the pyramids on the (111) face. These observations were consistent with unidirectional crystal growth originating from the face showing the pyramids.
Description: © The Electrochemical Society, Inc. 2009. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version is available at the link below.
URI: http://jes.ecsdl.org/content/156/11/J326
http://bura.brunel.ac.uk/handle/2438/8909
DOI: http://dx.doi.org/10.1149/1.3207950
ISSN: 0013-4651
Appears in Collections:Wolfson Centre for Materials Processing

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