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Concentration-Tuned Emission Phosphor

IP.com Disclosure Number: IPCOM000101370D
Original Publication Date: 1990-Aug-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Perry, PB: AUTHOR

Abstract

Luminescence material is required for displays as well as other uses. Because of the visual fatigue associated with long-term viewing of the popular green displays, it has been determined that a white display would be preferable both because of its low fatigue coefficient as well as its high visual response characteristics.

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Concentration-Tuned Emission Phosphor

       Luminescence material is required for displays as well as
other uses.  Because of the visual fatigue associated with long-term
viewing of the popular green displays, it has been determined that a
white display would be preferable both because of its low fatigue
coefficient as well as its high visual response characteristics.

      Use is made of a phosphor of fluorozirconate-based glass, doped
with europium fluoride.  The host glass can be synthesized with a
wide range of concentration of the constituents.  The three
constituents are ZrF4, BaF2, and ThF4.  Glass is formed at all but
low BaF2 concentration. The range is given in (*).  This phosphor is
synthesized by the mixing of a glass frit of (.615 ZrF4 + .308 BaF2 +
.077 ThF4)100-x + (EuF3) and heated with 60 ccs of NH4HF at 900oC for
a half an hour.  This is then poured into an aluminum mold at 200oC
and slowly cooled to room temperature.  For varying values of x, the
resulting emission spectra of this glass show unique and highly
desirable features.  The spectra for x = 1,5,15% are shown in Fig. 1.
At low values of x, the green emission 11 is large and the red
emission 12 is small. For high values of x, the red emission 12 is
large and the green emission 12 is small.  The dependence of the
oscillator strengths of the main emission lines versus concentration
is shown in Fig. 2.  We see that we can select the color of the
phosphor by tuning the concentratio...