An oxide phosphor that is highly durable and produces visible light when excited by exposure to near-ultraviolet excitation light, comprising an oxide having the composition represented by the formula (Al 2 O 3 ) x .(SiO 2 ) 1-x , where 0<x<1, and an activating element M.
1. An oxide phosphor comprising:
an oxide having a composition represented by formula (1); and
an activating element M,
wherein M is selected from the group consisting of Ce, Sm, Eu, Yb, Dy and Ag, and
wherein the additive amount of M is 0.06 mol % relative to the total amount(mol) of Al and Si:
formula (1) (Al 2 O 3 ) x .(SiO 2 ) 1-x wherein x in formula (1) is in the range of:0.5≦x ≦0.7.
2. The oxide phosphor according to claim 1 , wherein the oxide, having a composition represented by formula (1), is mullite.
3. The oxide phosphor according to claim 2 , wherein the mullite is 3Al 2 O 3 .2SiO 2 , 3Al 2 O 3 .1.75SiO 2 , or 3Al 2 O 3 .1.5SiO 2 .
4. A luminescent apparatus comprising:
a phosphor layer comprising the oxide phosphor according to claim 1 ; and
a luminous device that generates light exciting the oxide phosphor.