Europium-activated alkaline-earth chloroapatite phosphor and light-emitting device thereof
AssigneeToshiba Materials Co., Ltd.
InventorsNaotoshi Matsuda, Tatsunori Itoga, Masahiko Yamakawa, Hirofumi Takemura, Yasuhiro Shirakawa
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Abstract
A phosphor according to an embodiment is a europium-activated alkaline-earth chloroapatite phosphor having a composition expressed by a composition formula: (M1-xEux)5(PO4)3Cl, where M is an alkaline-earth element containing at least Sr and Ba, x is an atomic ratio satisfying 0.04≤x≤0.2. In the phosphor of this embodiment, absorptance of light at a wavelength of 400 nm is 90% or more, and absorptance of light at a wavelength of 650 nm is 2% or less.
Claims6
A europium-activated alkaline-earth chloroapatite phosphor comprising a composition expressed by a composition formula of (M1−x Eux)5(PO4)3Cl,
- wherein M is an alkaline-earth element containing at least Sr and Ba, and x is an atomic ratio satisfying 0.07≤x≤0.17,
- wherein an absorptance of light at a wavelength of 400 nm is 90% or more, and an absorptance of light at a wavelength of 650 nm is 2% or less, and
- wherein a light emission efficiency of the phosphor excited by near-ultraviolet to blue-violet light, having a peak wavelength in a range of 390 nm or more and 420 nm or less, is 83% or more.
Dependencies are inferred from the claim text.