1. A light emitting device comprising:
a light emitting structure comprising a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer to emit a light of a first wavelength range; and
a re-emission layer disposed on the light emitting structure, the re-emission layer comprising a nitride semiconductor,
wherein the re-emission layer absorbs the light of the first wavelength range and the re-emission layer emits a light of a second wavelength range longer than the first wavelength range, and
wherein the re-emission layer includes multi layers having different indium (In) compositions, respectively, and the indium content in the multi-layers is largest in a top layer of the multi-layers,
wherein a top surface of the light emitting structure has a concavo-convex structure, and a top surface of the re-emission layer has a concavo-convex structure according to the concavo-convex structure of the top surface of the light emitting structure.
2. The light emitting device of claim 1, wherein the light of the first wavelength range comprises a blue light.
3. The light emitting device of claim 1, wherein the light of the first wavelength range comprises a UV light.
4. The light emitting device of claim 1, wherein the re-emission layer comprises an InGaN layer.
5. The light emitting device of claim 1, wherein the re-emission layer comprises INxAlyGa1-x-yN layer, wherein 0\u2266x,y\u22661.
6. The light emitting device of claim 1, wherein the re-emission layer is disposed on the concavo-convex structure of the light emitting structure, with a predetermined thickness.
7. The light emitting device of claim 1, wherein the re-emission layer is conformally coated on the light emitting structure.
8. The light emitting device of claim 1, wherein the re-emission layer is disposed on the first conductivity type semiconductor layer or the second conductivity type semiconductor layer.
9. The light emitting device of claim 1, wherein the re-emission layer is disposed on the first or the second conductivity type semiconductor layer wherein the first or the second conductivity semiconductor layer is n-type or p-type.
10. The light emitting device of claim 1, further comprising:
an electrode disposed on the re-emission layer.
11. The light emitting device of claim 10, wherein the electrode comprises a metal selected from a group consisting of molybdenum, chromium (Cr), nickel (Ni), gold (Au), aluminum (Al), titanium (Ti), platinum (Pt), vanadium (V), tungsten (W), lead (Pd), copper (Cu), rhodium (Rh) and iridium (Ir) or an alloy of the metals.
12. The light emitting device of claim 10, wherein a lower surface of the electrode has a concavo-convex structure according to the concavo-convex structure of the top surface of the re-emission layer.
13. The light emitting device of claim 1, further comprising:
an ohmic layer disposed on the second conductivity type semiconductor layer.
14. The light emitting device of claim 13, wherein the ohmic layer comprises at least one selected from a group consisting of ITO, IZO, IZTO, IAZO, IGZO, IGTO, AZO, ATO, GZO, IZON, AGZO, IGZO, ZnO, IrOx, RuOx, NiO, RuOxITO, NiIrOxAu, NiIrOxAuITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, Au and Hf.
15. The light emitting device of claim 13, further comprising:
a metal support disposed on the ohmic layer.
16. The light emitting device of claim 15, wherein the metal support comprises at least one material selected from a group consisting of a group of Mo, Si, W, Cu and Al or an alloy of the group, Au, CuAlloy, Ni-nickel, Cu\u2014W and carrier wafer.
17. The light emitting device of claim 1, wherein the re-emission layer is disposed on a surface of the first conductivity type semiconductor layer and a surface of the second conductivity type semiconductor layer.
18. A light emitting device package comprising:
a package body;
a light emitting device disposed on the package body; the light emitting device comprising a light emitting structure comprising a first conductivity type semiconductor layer, an active layer on the first conductivity type semiconductor layer to emit a light of a first wavelength range and a second conductivity type semiconductor layer on the active layer, with a second electrode; and a re-emission layer disposed on the second conductivity type semiconductor layer, the re-emission layer comprising a nitride semiconductor to absorb the light of the first wavelength range, to emit a light of a second wavelength range longer than the first wavelength range;
first and second electrode layers disposed on the package body, the first and second electrode layers connected with the light emitting device; and
a filling material configured to surround the light emitting device,
wherein the re-emission layer includes multi-layers having different indium (In) compositions, respectively, and the indium content in the multi-layer is largest in a top layer of the multi-layers, and
wherein a top surface of the light emitting structure has a concavo-convex structure, and a top surface of the re-emission layer has a concavo-convex structure according to the concavo-convex structure of the top surface of the light emitting structure.
19. The light emitting device package of claim 18, wherein a lower surface of the second electrode has a concavo-convex structure according to the concavo-convex structure of the top surface of the re-emission layer.
20. A lightening system comprising:
a light source module comprising a substrate and a light emitting device disposed on the substrate;
a light guide plate configured to guide a light emitted from the light source module;
an optical sheet disposed on a front surface of the light guide plate, to diffuse the light guided from the light guide plate; and
a bottom cover configured to receive the light source module, the light guide plate and the optical sheet therein,
wherein the light emitting device comprises a light emitting structure comprising a first conductivity type semiconductor layer, an active layer on the first conductivity type semiconductor layer to emit a light of a first wavelength range, and a second conductivity type semiconductor layer on the active layer, with a second electrode disposed thereon; and a re-emission layer on the second conductivity type semiconductor layer, the re-emission layer comprising a nitride semiconductor to absorb the light of the first wavelength range, to emit a light of a second wavelength range longer than the first wavelength range,
wherein the re-emission layer includes multi-layers having different indium (In) compositions, respectively, and the indium content in the multi-layer is largest in a top layer of the multi-layers, and
wherein a top surface of the light emitting structure has a concavo-convex structure, and a top surface of the re-emission layer has a concavo-convex structure according to the concavo-convex structure of the top surface of the light emitting structure.
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. An apparatus for aligning electronic components comprising:
a positioning member having at least one formation for receiving an electronic component;
said at least one formation having lateral boundaries for constraining movement of the electronic component;
an alignment mechanism for providing a force for actively aligning one or more electronic components placed in said at least one formation with a lateral boundary of said at least one formation; and
a vibrating device for causing the positioning member to vibrate.
2. The apparatus of claim 1 wherein the positioning member has a plurality of formations for receiving electronic components, the formations having lateral boundaries for constraining movement of the electronic components.
3. The apparatus of claim 2 wherein the plurality of formations is a plurality of cavities in the positioning member and said lateral boundaries are sidewalls of the cavities.
4. The apparatus of claim 1 comprising a tilting mechanism for tilting the positioning member so that the electronic components are aligned with lateral boundaries of said cavities under force of gravity.
5. The apparatus of claim 1 comprising a heater for heating the positioning member for aligning and welding the one or more electronic components.
6. The apparatus of claim 1 wherein the alignment mechanism comprises one or more actuators for each formation for pushing the electronic components into alignment with a lateral boundary of the formation.
7. The apparatus of claim 2 wherein the positioning member has a first layer having a plurality of formations for receiving first electronic components and a second layer having a plurality of formations for receiving second electronic components.
8. The apparatus of claim 1 wherein the alignment mechanism provides a force for aligning the electronic component with two adjoining lateral boundaries of said at least one formation.
9. An apparatus for aligning electronic components comprising:
a positioning member having at least one formation for receiving an electronic component;
said at least one formation having lateral boundaries for constraining movement of the electronic component; and
an alignment mechanism for providing a force for actively aligning one or more electronic components placed in said at least one formation with a lateral boundary of said at least one formation;
wherein the at least one formation is a cavity in the positioning member and wherein the alignment mechanism is a vacuum channel for applying suction force to the cavity so as to draw the one or more electronic components into alignment with a side wall of the cavity.
10. The apparatus of claim 9 wherein the suction force is applied to a corner of the cavity so as to draw said one or more electronic components to the corner of the cavity until contacting with two adjoining walls of the cavity.