Europium- and strontium-based phosphor
AssigneeMitsubishi Chemical Corporation
InventorsHiromu Watanabe, Masumi Itou, Keiichi Seki, Hiroshi Wada, Motoyuki Shigeiwa, Kaoru Terada, Naoto Kijima
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Abstract
A nitride phosphor contains europium as an activating element and strontium, or strontium and calcium, as divalent metal elements. The phosphor further includes aluminum and silicon. Of the europium in the phosphor, at least 85% is in the form of Eu2+. The phosphor has a peak emission wavelength of from 590 nm to 650 nm. A phosphorescent body that includes the phosphor can be suitable for converting a wavelength of at least a portion of light emitted from an excitation light source in a light-emitting device.
Claims7
A phosphor of formula:
- M1′a′Srb′Cac′M2′d′Ale′Sif′Ng′
- wherein a′, b′, c′, d′, e′, f′, and g′ satisfy:
- 0.00001≦a′≦0.15;
- 0.6≦b′≦0.99999;
- 0≦c′<1;
- 0≦d′<1;
- a′+b′+c′+d′=1;
- 0.5≦e′≦1.5;
- 0.5≦f′≦1.5;
- and
- 2.5≦g′≦3.5;
- M1′ is Eu;
- M2′ is Mg, Ba, or both;
- at least 85 mol % of M1′ is Eu2+;
- the phosphor has a peak emission wavelength of from 590 nm to 650 nm;
- and
- the phosphor comprises oxygen in an amount of 5 wt % or less.
Dependencies are inferred from the claim text.