Phosphors and light emitting device using the same
View Patent ↗There are provided phosphors having high luminous efficiency at desired wavelengths and good light output stability and a light emitting device using the same. A phosphor according to an aspect of the invention includes a sulfide crystallographic phase and an oxide crystallographic phase. Here, the phosphor is a multiphase compound in which the sulfide crystallographic phase and the oxide crystallographic phase exist together.
1. A phosphor, comprising:
a sulfide crystallographic phase; and
an oxide crystallographic phase,
wherein the phosphor is a multiphase compound in which the sulfide crystallographic phase and the oxide crystallographic phase exist together,
wherein the sulfide crystallographic phase is strontium thiogallate (SrGa 2 S 4 ),
wherein the oxide crystallographic phase is a magnesium gallium oxide (MgGa 2 O 4 ).
2. The phosphor of claim 1 , further comprising:
an activator,
wherein the activator comprises at least one rare earth element.
3. The phosphor of claim 2 , wherein the activator comprises at least one element selected from a group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.
4. The phosphor of claim 2 , further comprising:
a co-activator,
wherein the co-activator comprises at least one element selected from a group consisting of chlorine, bromine, and lithium.
5. The phosphor of claim 1 , wherein the phosphor includes: Eu 2+ .
6. A light emitting device, comprising:
a light source; and
a phosphor absorbing light emitted from the light source to emit light,
wherein the phosphor includes a sulfide crystallographic phase and an oxide crystallographic phase, and the phosphor is a multiphase compound in which the sulfide crystallographic phase and the oxide crystallographic phase exist together,
wherein the sulfide crystallographic phase is strontium thiogallate (SrGa 2 S 4 ),
wherein the oxide crystallographic phase is a magnesium gallium oxide (MgGa 2 O 4 ).
7. The light emitting device of claim 6 , wherein the light source is any one of a light emitting diode or a laser diode.
8. The light emitting device of claim 6 , wherein the light source emits light with a wavelength ranging from 400 to 480 nm.
9. The light emitting device of claim 6 , wherein the phosphor comprises: Eu 2+ .
10. The light emitting device of claim 8 , further comprising a red phosphor.
11. The light emitting device of claim 10 , wherein the light emitting device is a blue light emitting diode, and the multiphase compound is a green phosphor.
12. The light emitting device of claim 11 , wherein the green phosphor comprises: Eu 2+ .