Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of slanting air voids tapering away from the substrate and an opening over each of the slanting air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the slanting air voids in a shape of trapezoid with the first epitaxial layer.

Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of slanting air voids tapering away from the substrate and an opening over each of the slanting air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the slanting air voids in a shape of trapezoid with the surface and the first epitaxial layer.

Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of slanting air voids tapering away from the substrate and an opening over each of the slanting air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the slanting air voids in a shape of trapezoid with the first epitaxial layer.

Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of stepped air voids and an opening over each of the stepped air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the stepped air voids with the first epitaxial layer.

Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of stepped air voids and an opening over each of the stepped air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the stepped air voids with the surface and the first epitaxial layer.

Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of slanting air voids tapering away from the substrate and an opening over each of the slanting air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the slanting air voids in a shape of trapezoid with the surface and the first epitaxial layer.

Abstract: An epitaxial structure includes a substrate, a first epitaxial layer and a second epitaxial layer. The substrate has a surface, and the first epitaxial layer is disposed over the substrate and defines a plurality of stepped air voids and an opening over each of the stepped air voids. The second epitaxial layer is disposed on the first epitaxial layer and collectively defines the stepped air voids with the surface and the first epitaxial layer.

Abstract: An epitaxial growth method includes the steps of: providing a substrate; forming a sacrifice layer on the substrate; patterning the sacrifice layer to form a plurality of bumps spaced apart from each other on the substrate; epitaxially forming a first epitaxial layer on the substrate to cover a portion of each of the bumps; removing the bumps to form a plurality of cavities; and epitaxially forming a second epitaxial layer on the first epitaxial layer such that the cavities are enclosed by the first epitaxial layer and the second epitaxial layer. An epitaxial structure grown by the method is disclosed as well.

Abstract: The present invention provides a light emitting diode (LED) element which comprises a substrate, a buffer layer, a plurality of nano-spheres and a light emitting structure. The substrate comprises a plurality of grooves arranged at intervals on a surface of the substrate. The buffer layer is disposed on the surface of the substrate where the grooves being formed, wherein the grooves are disposed between the substrate and the buffer layer. The nano-spheres are received in the grooves, so each groove is provided with at least a nano-sphere. The light emitting structure is disposed on the buffer layer.

Abstract: An epitaxial growth method includes the steps of: providing a substrate; forming a sacrifice layer on the substrate; patterning the sacrifice layer to form a plurality of bumps spaced apart from each other on the substrate; epitaxially forming a first epitaxial layer on the substrate to cover a portion of each of the bumps; removing the bumps to form a plurality of cavities; and epitaxially forming a second epitaxial layer on the first epitaxial layer such that the cavities are enclosed by the first epitaxial layer and the second epitaxial layer. An epitaxial structure grown by the method is disclosed as well.

Abstract: The present invention provides a light emitting diode (LED) element which comprises a substrate, a buffer layer, a plurality of nano-spheres and a light emitting structure. The substrate comprises a plurality of grooves arranged at intervals on a surface of the substrate. The buffer layer is disposed on the surface of the substrate where the grooves being formed, wherein the grooves are disposed between the substrate and the buffer layer. The nano-spheres are received in the grooves, so each groove is provided with at least a nano-sphere. The light emitting structure is disposed on the buffer layer.