LIGHT EMITTING DEVICE AND LIGHT EMITTING DEVICE PACKAGE HAVING THE SAME
Disclosed are a light emitting device and a light emitting device package having the same. The light emitting device includes a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first conductive semiconductor layer and the second conductive semiconductor layer, an electrode electrically connected to the first conductive semiconductor layer, a reflective layer under the second conductive semiconductor layer, a protective layer disposed around a lower surface of the second conductive semiconductor layer, and a buffer layer disposed on at least one of top and lower surfaces of the protective layer.
1 . A semiconductor light emitting device comprising:
a plurality of compound semiconductor layers including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first and second conductive semiconductor layers;
an electrode disposed on the compound semiconductor layers;
a reflective layer under the compound semiconductor layers;
a protective layer at an outer peripheral portion of a lower surface of the compound semiconductor layers; and
a buffer layer at least one of top and lower surfaces of the protective layer.
2 . The semiconductor light emitting device of claim 1 , wherein an inner portion of the protective layer makes contact with the outer peripheral portion of the lower surface of the plurality of the compound semiconductor layers.
3 . The semiconductor light emitting device of claim 1 , wherein the buffer layer extends from the lower surface of the protective layer to a lateral surface of the protective layer.
4 . The semiconductor light emitting device of claim 1 , wherein the buffer layer extends from the top surface of the protective layer to a lateral surface of the protective layer.
5 . The semiconductor light emitting device of claim 1 , wherein the buffer layer is formed along an outer portion of the protective layer.
6 . The semiconductor light emitting device of claim 1 , wherein the buffer layer has a single layer structure or a multiple layer structure including at least one selected from the group consisting of Ti, Ni, W, Pt, Pd, Cu, Mo, In, and Sn or including a plurality of mixture materials.
7 . The semiconductor light emitting device of claim 1 , wherein the buffer layer has a thickness less than or equal to a thickness of the protective layer or a thickness of about 1 μm to about 10 μm.
8 . The semiconductor light emitting device of claim 1 , wherein the reflective layer includes an ohmic material, a reflective material, or the ohmic and reflective materials.
9 . The semiconductor light emitting device of claim 1 , further comprising an ohmic layer including conductive oxide material between the reflective layer and the compound semiconductor layer and making ohmic contact with the lower surface the compound semiconductor layers.
10 . The semiconductor light emitting device of claim 1 , further comprising a current blocking layer having electrical conductivity lower than electrical conductivity of the reflective layer, at least a portion of the current blocking layer overlapping with the electrode vertically under the plurality of the compound semiconductor layers.
11 . The semiconductor light emitting device of claim 1 , further comprising at least one of an adhesion layer and a conductive support member under the reflective layer.
12 . The semiconductor light emitting device of claim 9 , wherein the ohmic layer makes contact with a portion of a lower surface of the protective layer or an entire portion of the lower surface of the protective layer.
13 . The semiconductor light emitting device of claim 11 , wherein the buffer layer is disposed between the protective layer and the reflective layer or the adhesion layer.
14 . The semiconductor light emitting device of claim 9 , wherein the protective layer or the ohmic layer includes at least one of transmissive nitride material, transmissive oxide material, and transmissive insulating material.
15 . The semiconductor light emitting device of claim 14 , wherein the protective layer includes at least one selected from the group consisting of ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminum zinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), GZO (gallium zinc oxide), SiO 2 , SiO x , SiO x N y , Si 3 N 4 , Al 2 O 3 , and TiO 2 .
16 . The semiconductor light emitting device of claim 1 , further comprising an insulating layer at an outer peripheral portion of the plurality of the compound semiconductor layers.
17 . The semiconductor light emitting device of claim 5 , wherein the buffer layer has a single layer structure or a multiple layer structure including at least one selected from the group consisting of Ti, Ni, W, Pt, Pd, Cu, Mo, In, and Sn or including a plurality of mixture materials.
18 . The semiconductor light emitting device of claim 9 , further comprising a current blocking layer having electrical conductivity lower than electrical conductivity of the reflective layer, at least a portion of the current blocking layer overlapping with the electrode vertically under the plurality of the compound semiconductor layers.