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AssigneeDowa Electronics Materials Co., Ltd.
InventorsAkira Nagatomi, Kenji Sakane
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To provide a phosphor having an emission spectrum with a broad peak in a range from green color to yellow color, having a broad and flat excitation band capable of using lights of broad range from near ultraviolet/ultraviolet to blue lights as excitation lights, and having excellent emission efficiency and luminance. The problem is solved by providing the phosphor expressed by a general composition formula MmAaBbOoNn:Z (where element M is one or more kinds of elements having bivalent valency, element A is one or more kinds of elements having tervalent valency, element B is one or more kinds of elements having tetravalent valency, O is oxygen, N is nitrogen, and element Z is one or more kinds of elements acting as the activator), satisfying 4.0<(a+b)/m<7.0, a/m=0.5, b/a>2.5, n>o, n=2/3m+a+4/3b−2/3o, and having an emission spectrum with a peak wavelength of 500 nm to 650 nm when excited by light in a wavelength range from 300 nm to 500 nm.
A phosphor, which is given as a general composition formula expressed by MmAaBbOoNn:Z, (where element M is Sr, element A is Al, element B is Si, O is oxygen, N is nitrogen, and element Z is at least one of Ce or Eu), satisfying 4.0<(a+b)/m<7.0, b/a>2.5, n>o, n=2/3m+a+4/3b−2/3o, 1.1<a/m≦1.5, 3.5≦b/m≦4.5, and 0.48≦o/m≦0.81 wherein when excited by light in a wavelength range from 300 nm to 500 nm, the phosphor has an emission spectrum with a peak wavelength in a range from 500 nm to 650 nm.
A phosphor sheet, comprising:
Dependencies are inferred from the claim text.