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Color stable red-emitting phosphors

A color stable, phosphor technology, applied in electroluminescent light sources, luminescent materials, light sources, etc.

Active Publication Date: 2017-08-18
GE LIGHTING SOLUTIONS LLC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Although using Mn 4+ The efficacy and CRI of lighting systems with doped fluoride hosts can be quite high, but a potential limitation is their sensitivity to degradation and high luminous flux under high temperature and high humidity (HTHH) conditions

Method used

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  • Color stable red-emitting phosphors
  • Color stable red-emitting phosphors
  • Color stable red-emitting phosphors

Examples

Experimental program
Comparison scheme
Effect test

example

[0088] General procedure

[0089] Silicone tape sample preparation

[0090] Samples were prepared by mixing 500 mg of the material to be tested with 1.50 g of silicone (Sylgard 184). The mixture was degassed in a vacuum chamber for about 15 minutes. The mixture (0.70 g) was poured into a dish formwork (28.7 mm diameter, 0.79 mm thickness) and baked at 90° C. for 30 minutes. Samples were cut into squares measuring approximately 5mm x 5mm for testing.

[0091] stability test

[0092] High Luminous Flux Conditions

[0093] A laser diode emitting at 446 nm is coupled to an optical fiber with a collimator at its other end. The power output was 310 mW and the beam diameter of the sample was 700 microns. This is equivalent to 80W / cm on the sample surface 2 flux. Spectral power distribution (SPD) spectra, which are the combined scattered radiation from the laser and emission from the excited phosphor, were collected with a 1 meter (diameter) integrating sphere and the data pro...

example 7

[0115] Slow cooling after example 7 annealing

[0116] Commercial K with 0.70% manganese content (as determined by inductively coupled plasma) 2 SiF 6 :Mn 4+ The phosphor was placed in a furnace under an atmosphere of nitrogen (80%) and fluorine (20%) at 10 psia and heated at 540°C for 8 hours. After 8 hours, the temperature was decreased at a rate of 1 °C / min. The annealed phosphor was treated with K 2 SiF 6 Wash in saturated 49% HF solution, dry under vacuum and sieve.

[0117] The stability of the phosphors of Comparative Example 2 and Example 7 was evaluated and compared to an untreated commercial control having a manganese content of 0.70%. Annealing improves stability and using slow cooling further reduces % strength loss.

[0118] Examples 8-23 have K with manganese levels ranging from 1.1 wt% to 5.3 wt% 2 SiF 6 :Mn 4+

[0119] Comparative Examples 3-5 have K with manganese levels ranging from 0.52% to 0.79% by weight 2 SiF 6 :Mn 4+

[0120] The Mn-doped ...

example 24

[0124] Example 24 K with a color temperature of 3000°K 2 SiF 6 :Mn 4+ blend

[0125] The Mn-doped potassium fluorosilicate materials of Examples 2, 3, and 10 were blended with YAG, and ribbons were prepared to emit light with a color temperature of 3000°K.

[0126] The composition of the blend is shown in Table 6.

[0127] Table 6

[0128] Blend Composition

[0129]

[0130] Table 6

[0131] Blend Composition

[0132]

[0133] It can be seen that significantly less red phosphor material with a higher Mn concentration is used than material with a lower Mn concentration.

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Abstract

A process for synthesizing a Mn doped phosphor includes contacting a precursor of formula I, Ax [MFy]:Mn4+ I at an elevated temperature with a fluorine-containing oxidizing agent in gaseous form to form the color stable Mn4+ doped phosphor; wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; y is 5, 6 or 7; and amount of Mn ranges from about 0.9 wt% to about 4 wt%, based on total weight.

Description

[0001] Cross References to Related Applications [0002] This patent application is a continuation-in-part of US Application Serial No. 14 / 302823 filed June 12, 2014 and claims priority from said US Application, which is hereby incorporated by reference in its entirety. Background technique [0003] Based on Mn 4+ Red emitting phosphors of activated complex fluoride materials such as those described in US 7,358,542, US 7,497,973 and US 7,648,649 can be combined with yellow / green emitting phosphors such as YAG:Ce or other garnet compositions Utilized in combination to achieve warm white light (on the black body locus (CCT<5000K, color rendering index (CRI)>80) from blue LEDs equivalent to that produced by current fluorescent, incandescent and halogen lamps of the kind. These materials strongly absorb blue light and emit efficiently between about 610-635nm with little deep red / NIR emission. Thus, luminous efficiency is maximized compared to red phosphors, which The body...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/61H01L33/50
CPCC09K11/617H01L33/502C09K11/7774H01L2924/181H01L2224/48247H01L2224/48257Y02B20/00H01L2924/00012H05B33/14
Inventor J.E.墨菲F.加西亚A.I.乔扈里S.P.西斯塔A.A.塞特卢尔
Owner GE LIGHTING SOLUTIONS LLC