1. A light emitting device comprising:
a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer;
a buffer layer on the light emitting structure; and
a filter layer on the buffer layer,
wherein the filter layer comprises:
a first dielectric layer having a first refractive index; and
a second dielectric layer on the first dielectric layer, the second dielectric layer having a second refractive index different from the first refractive index.
2. The light emitting device according to claim 1, wherein the buffer layer comprises a hollow space part.
3. The light emitting device according to claim 2, further comprising a support layer between the filter layer and the light emitting structure.
4. The light emitting device according to claim 3, wherein the support layer comprises one of copper (Cu) and gold (Au).
5. The light emitting device according to claim 1, wherein the buffer layer comprises a material having a refractive index between a refractive index of air and a refractive index of the filter layer.
6. The light emitting device according to claim 5, wherein the buffer layer comprises at least one of spin-on-glass and MgF2.
7. The light emitting device according to claim 1, wherein a thickness of the first dielectric layer and a thickness of the second dielectric layer is \u03bb(4n\xd7cos\u03b8), where \u03bb is a wavelength of long-wavelength light to be reflected, n is a reflective index of a dielectric layer, and \u03b8 is an incident angle of light to a substrate.
8. The light emitting device according to claim 1, further comprising a phosphor layer on the filter layer.
9. The light emitting device according to claim 1, further comprising a passivation member at a lower periphery of the light emitting structure.
10. The light emitting device according to claim 1, further comprising:
at least one electrode on the light emitting structure; and
a conductive or non-conductive substrate under the light emitting structure.
11. A light emitting device comprising:
a light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first conductive type semiconductor layer and the second conductive type semiconductor layer;
a buffer layer on the light emitting structure; and
a filter layer on the buffer layer.
12. The light emitting device according to claim 11 wherein the buffer layer comprises an air gap or a hollow space part.
13. The light emitting device according to claim 11, wherein the buffer layer comprises a material having a refractive index between a refractive index of air and a refractive index of the filter layer.
14. The light emitting device according to claim 11, wherein the buffer layer comprises at least one of spin-on-glass and MgF2.
15. The light emitting device according to claim 11, further comprising a pattern on the buffer layer.
16. The light emitting device according to claim 11, wherein the filter layer comprises:
a first dielectric layer having a first refractive index; and
a second dielectric layer on the first dielectric layer, the second dielectric layer having a second refractive index different from the first refractive index.
17. The light emitting device according to claim 16, wherein a thickness of the first dielectric layer and a thickness of the second dielectric layer are \u03bb(4n\xd7cos\u03b8), where \u03bb is a wavelength of long-wavelength light to be reflected, n is a reflective index of a dielectric layer, and \u03b8 is an incident angle of light to a substrate.
18. The light emitting device according to claim 11, further comprising a phosphor layer on the filter layer.
19. The light emitting device according to claim 11, further comprising:
at least one electrode on the light emitting structure; and
a conductive or non-conductive substrate under the light emitting structure.
20. A light emitting device package comprising:
a package body;
at least one electrode layer on the package body; and
a light emitting device of claim 1 electrically connected to the electrode layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A deterioration analysis method, comprising irradiating a polymer material with a metal coating having a thickness of 100 \u212b or less formed thereon, with high intensity X-rays, and measuring X-ray absorption while varying the energy of the X-rays, to analyze deterioration of the polymer.
2. The deterioration analysis method according to claim 1, wherein the metal coating is a vapor deposited metal film.
3. The deterioration analysis method according to claim 1, wherein the polymer material is a tire rubber composition.
4. The deterioration analysis method according to claim 3, wherein the tire rubber composition has a carbon black content of 50 parts by mass or less per 100 parts by mass of a rubber component of the tire rubber composition.
5. A chemical state measurement method, comprising removing blooms on the surface of a rubber material and then applying an X-ray-based surface analysis method to measure the chemical state on the surface of the rubber material.
6. The chemical state measurement method according to claim 5, comprising examining a change in chemical state occurring starting from the surface of the rubber material to measure deterioration of the rubber material.
7. The chemical state measurement method according to claim 5, wherein the blooms on the surface of the rubber material are removed using a solvent.
8. The chemical state measurement method according to claim 7, wherein the solvent is an organic solvent.
9. The chemical state measurement method according to claim 5, wherein the blooms on the surface of the rubber material are removed using a solvent extraction method.