Rare-earth-activated phosphors

Details Rare-earth-activated phosphors Rare-earth-activated phosphors

2001-09-14

2004-08-31

Le, H. Thi (Department: 1773)

Stock material or miscellaneous articles

Coated or structually defined flake, particle, cell, strand,...

Particulate matter

C252S30140R, C423S021100, C423S050000, C423S263000, C423S579000, C423S599000, C428S403000

Reexamination Certificate

active

06783855

ABSTRACT:

The present invention relates to rare earth activated phosphors. Such phosphors are known to possess excellent light output and colour rendering properties and have been utilized successfully in many display technologies. One particularly successful material, europium activated yttrium oxide (Y
2
O
3
:Eu
3+
), has shown particular promise in the field of field emission display; yttrium oxide acts as a host for the Eu
3+
or dopant ion.
The successful introduction of field emitting displays is dependent upon the availability of low voltage phosphors. As the phosphor exciting electrons have a comparatively low energy (less than 2 kV) as compared to conventional phosphors and one must avoid the use of sulphur to reduce contamination, new types of material have to be used. In particular, it is desirable to be able to make the phosphor particles without a surface dead layer which occurs when fine particles are prepared using a conventional grinding technique. This dead layer is an important source of non-radiative luminescence routes for low energy electrons.
According to the present invention there is provided a process for preparing phosphor particles of a host oxide doped with a rare earth or manganese without the need for a grinding technique which comprises:
preparing an aqueous solution of salts of the host ion and of the dopant ion and a water soluble compound which decomposes under the reaction conditions to convert said salts into hydroxycarbonate,
heating the solution so as to cause said compound to decompose,
recovering the resulting precipitate and
calcining it at a temperature of at least 500° C.


REFERENCES:
patent: 3457184 (1969-07-01), Kobayashi, et al.
patent: 3668143 (1972-06-01), Luckey
patent: 4032471 (1977-06-01), Luckey
patent: 5250366 (1993-10-01), Nakajima et al.
patent: 5413736 (1995-05-01), Nishisu et al.
patent: 5518808 (1996-05-01), Bruno et al.
patent: 5637258 (1997-06-01), Goldburt et al.
patent: 5985176 (1999-11-01), Rao
patent: 6036886 (2000-03-01), Chhabra et al.
patent: 24 02 269 (1975-07-01), None
patent: 42 10 153 (1992-03-01), None
patent: 0 253 552 (1988-01-01), None
patent: 0 684 072 (1995-11-01), None
patent: 0 732 356 (1996-09-01), None
patent: 2 677 139 (1992-05-01), None
patent: 2 026 530 (1980-02-01), None
patent: 2 084 395 (1982-04-01), None
patent: 46031844 (1971-09-01), None
patent: 63146981 (1988-06-01), None
patent: 5279022 (1993-10-01), None
patent: 5320637 (1993-12-01), None
patent: 5279023 (1994-02-01), None
patent: 6174854 (1994-06-01), None
patent: 6322363 (1994-11-01), None
patent: 7097211 (1995-04-01), None
patent: 9188517 (1997-07-01), None
patent: 1 458 700 (1976-12-01), None
patent: 8 202 824 (1983-02-01), None
patent: 2008319 (1994-02-01), None
patent: WO 82/03876 (1982-11-01), None
patent: WO 96/01297 (1996-01-01), None
patent: WO 97/35943 (1997-10-01), None
patent: WO 98/10459 (1998-03-01), None
patent: WO 99/46204 (1999-09-01), None
patent: WO 00/36051 (2000-06-01), None
Sordelet et al.,J. Eur. Ceramic Soc. 14: 123-130 (1994).
Giesche and Matijevic,J. Mater. Res. 9(2): 436-450 (1994).
Cho, et al.,Phys. Lett, 71: (23), 3335-3337 (1997).
Bihari, et al.,J. Lumin., 75: 1-10 (1997).
Goldburt, et al.,J. Lumin., 72-74, 190-192, (1997).
Kobayashi,J. Mat. Sci. Letters, 11: 767-768, (Jun. 1992).
Phillips, et al.,27th Int. SAMPE Tech. Conf., 501-505 (Oct. 9-13, 1995).
Shea, et al.,J. Am. Cer. Soc., 79(12), 3257-3265 (Dec. 1996).
Sommerdijk, et al.,J. Lumin, 5(4), Abstract Only, (1972).
Maestro P: & Al: Mixed Rare Earth Oxides as Starting Material for Preparation of Y203:EU Lamp Phosphor: Characterization and Use, Journal of the Electrochemical Society, 1992, vol. 139, No. 5, pp. 1479 to 1482.

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