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Improved Growth Of Srga2s4 Thin Film Electroluminescence Phosphors

Published online by Cambridge University Press:  10 February 2011

D. Braunger
Affiliation:
Universitat Stuttgart, Institut fur Physikalische Elektronik, Pfaffenwaldring 47, 70569 Stuttgart, braunger@ipers I.e-technik.uni-stuttgart.de, Germany
T. A. Oberacker
Affiliation:
Universitat Stuttgart, Institut fur Physikalische Elektronik, Pfaffenwaldring 47, 70569 Stuttgart, braunger@ipers I.e-technik.uni-stuttgart.de, Germany
U. Troppenz
Affiliation:
Heinrich-Hertz-lnstitut, AG Elektrolumineszenz, Hausvogteiplatz 5-7, 10117 Berlin, Germany
H.-W. Schock
Affiliation:
Universitat Stuttgart, Institut fur Physikalische Elektronik, Pfaffenwaldring 47, 70569 Stuttgart, braunger@ipers I.e-technik.uni-stuttgart.de, Germany
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Abstract

Cerium activated ternary strontium thiogallate phosphor thin films have been deposited by multi-source evaporation of elemental strontium, gallium and sulfur as source materials. Cerium chloride (CeCI3) has been used as activator starting material. In order to avoid SrS as well as Ga phase segregations elemental In as well as compounds, such as LiF, NaF, LiCl, and SrCI2, have been investigated as possible growth enhancing agents.

Coevaporation of indium resulted in an improved crystallization with the drawback of an increased reabsorption of the cerium emission. The other additives lead to improved crystal quality combined with true-blue cathodoluminescence (CL) performance (C.I.E. color coordinates of up to 0. 14/0.12) which proves phosphor layers without any SrS phase segregations.

Thin film electroluminescent (TFEL) devices with SrGa2S4:CeCl3 phosphor layers prepared with LiF as additive exhibit highest ever reported L40 luminances of 78 cd/m2 and luminous efficiencies of 0.017 lm/W at a transferred charge of 1 μ;C/cm2 with 1 kHz / 50 μs bipolar square wave excitation.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

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