Nitride-based semiconductor light emitting device with light extraction layer formed within
View Patent ↗A nitride-based semiconductor light emitting device having an improved structure in which light extraction efficiency is improved and a method of manufacturing the same are provided. The nitride-based semiconductor light emitting device comprises an n-clad layer, an active layer, and a p-clad layer, which are sequentially stacked on a substrate, wherein the n-clad layer comprises a first clad layer, a second clad layer, and a light extraction layer interposed between the first clad layer and the second clad layer and composed of an array of a plurality of nano-posts, the light extraction layer diffracting or/and scattering light generated in the active layer.
1. A nitride-based semiconductor light emitting device comprising:
an n-clad layer, an active layer, and a p-clad layer, which are sequentially stacked on a substrate,
wherein the n-clad layer comprises a first n-clad layer, an array of a plurality of nano-posts formed on an upper surface of the first n-clad layer and a second n-clad layer on the upper surface of the first n-clad layer on which the nano-posts are formed, whereby the nano-posts are interposed between the first and second n-clad layers,
wherein the nano-posts are formed of a material having a different refraction index from a material used in forming the first n-clad layer and the second n-clad layer to diffract and/or scatter light generated in the active layer and each of nano-posts has a cylindrical shape by etching using a lithography method,
wherein the first n-clad and the second n-clad layer are formed of substantially the same material,
wherein the nano-posts are wholly encompassed by the substantially the same material forming the first and second n-clad layers.
2. The nitride-based semiconductor light emitting device of claim 1 , wherein the nano-posts are formed of a light transmission material having a refraction index of approximately 2.5 or less.
3. The nitride-based semiconductor light emitting device of claim 2 , wherein the nano-posts are formed of a transparent material with respect to a wavelength in a range of approximately 200-780 nm.
4. The nitride-based semiconductor light emitting device of claim 1 , wherein the nano-posts are formed of a material selected from the group consisting of SiO 2 , SiN x , Al 2 O 3 , HfO, TiO 2 , ZrO, and ZnO or by adding a material selected from the group consisting of Mg, Ag, Zn, Sc, Hf, Zr, Te, Se, Ta, W, Nb, Cu, Si, Ni, Co, Mo, Cr, Mn, Hg, Pr, and La to an indium oxide.
5. The nitride-based semiconductor light emitting device of claim 1 , wherein an arrangement period of the nano-posts is approximately 100-2000 nm.
6. The nitride-based semiconductor light emitting device of claim 5 , wherein an arrangement period of the nano-posts is approximately 700 nm.
7. The nitride-based semiconductor light emitting device of claim 1 , wherein a height of each of the nano-posts is approximately 100-1000 nm.
8. The nitride-based semiconductor light emitting device of claim 7 , wherein a height of each of the nano-posts is approximately 300 nm.
9. The nitride-based semiconductor light emitting device of claim 1 , wherein a diameter of each of the nano-posts is approximately 100-1000 nm.
10. The nitride-based semiconductor light emitting device of claim 1 , wherein the first clad layer and the second clad layer are formed of an AIInGaN-based III-V-group nitride semiconductor material.