Batentschuk M, Geisler R, Hum J, Iqbal F, Meister F, Osvet A, Stiegelschmitt A, Winnacker A (2012)
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2012
Publisher: Springer Verlag (Germany)
Book Volume: 106
Pages Range: 211-221
Journal Issue: 1
DOI: 10.1007/s00340-011-4735-5
The absolute majority of phosphors are composed of a host lattice and some percentage of an activator. At higher activator concentrations the concentration quenching occurs. However, there are phosphors in which only minor quenching of the emission occurs with increasing of the activator content. Based on the existence of two different valence states of the Eu ion (2+ and 3+), two approaches for the development of "concentrated phosphors", i.e. light emitting materials in which the activator ion is a main part of the crystal lattice, are discussed. In both approaches, reduced energy migration leading to the luminescence quenching is considered as a main condition to reach a high quantum efficiency of a concentrated phosphor. Two kinds of phosphors-Eu2+-doped alumosilicate and Eu3+-doped oxyfluoride-are used as an experimental basis for this discussion. Starting from the stoichiometric Ca1-x Eu-x(2+) A1(2)si(2)O8 anorthite and Eu3+OF oxyfluorides, the non-stoichiometric powders with Eu-0.92(2+) A1(1.76)Si(2.24)O(8), Eu3+(O, F)(2,35) and Eu3+(O, F)(2,16) compositions were synthesized by a solid state reaction and investigated. It was shown that-in spite of the almost 100% Eu concentration-light converters with high quantum efficiency of more than 45% can be realized. A possible application of these materials as UV LED light converters for white light emitting diodes are discussed as well.
APA:
Batentschuk, M., Geisler, R., Hum, J., Iqbal, F., Meister, F., Osvet, A.,... Winnacker, A. (2012). Eu2+ and Eu3+ based "concentrated phosphors" as converters for UV LED light: two approaches and two new examples. Applied Physics B-Lasers and Optics, 106(1), 211-221. https://dx.doi.org/10.1007/s00340-011-4735-5
MLA:
Batentschuk, Miroslaw, et al. "Eu2+ and Eu3+ based "concentrated phosphors" as converters for UV LED light: two approaches and two new examples." Applied Physics B-Lasers and Optics 106.1 (2012): 211-221.
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