▎ 摘　　要

NOVELTY - The epitaxial structure (20) comprises a substrate (200) having an epitaxial growth surface, an epitaxial layer (204) disposed on the substrate, and a patterned graphene layer (202) disposed between the substrate and the epitaxial layer and on the growth surface. The graphene layer is a pure graphene structure consisting of graphene and a continuous structure, comprises a graphene film consisting of a single layer of continuous carbon atoms and sub graphene layers spaced from each other, is a graphene powder coating, and defines apertures. A thickness of the graphene layer is 1 nm to 100 mu m. USE - The epitaxial structure is useful in light emitting devices such as LEDs based on group III-V nitride semiconductors such as gallium nitride. ADVANTAGE - The epitaxial structure reduces lattice mismatch and thermal expansion mismatch between gallium nitride and sapphire substrate or reduces bowing of the substrate thus preventing cracking in the fabrication of devices with small feature sizes. DETAILED DESCRIPTION - The epitaxial structure (20) comprises a substrate (200) having an epitaxial growth surface, an epitaxial layer (204) disposed on the substrate, and a patterned graphene layer (202) disposed between the substrate and the epitaxial layer and on the growth surface. The graphene layer is a pure graphene structure consisting of graphene and a continuous structure, comprises a graphene film consisting of a single layer of continuous carbon atoms and sub graphene layers spaced from each other, is a graphene powder coating, and defines apertures. A thickness of the graphene layer is 1 nm to 100 mu m. The epitaxial layer is disposed on the graphene layer, contacts the substrate through the apertures, and defines caves adjacent to the substrate. The apertures have sizes of 10 nm to 10 mu m, and are present in shapes of round, square, triangle, diamond or rectangle. The sub graphene layers are disposed in grooves. A dutyfactor of the graphene layer is 1:4-4:1, and is an area ratio between a covered part to an exposed part of the epitaxial growth surface. The caves and the substrate cooperatively form sealed chambers to receive the graphene layer. A material of the epitaxial layer is made of semiconductor, metal or alloy. DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an epitaxial structure. Epitaxial structure (20) Substrate (200) Graphene layer (202) Epitaxial layer. (204)