▎ 摘　　要

NOVELTY - Composite material comprises silica-coated quantum dots (11) and graphene nano-sheets (13) bound to the surface of the silica-coated quantum dots, where the silica-coated quantum dots include quantum dots and silica layer (12) is coated on the surface of the quantum dot. USE - The composite material is useful as light-emitting layer material of quantum dots light-emitting diode (claimed). ADVANTAGE - The composite material improves stability of quantum dots without affecting inherent optical properties of the quantum dots, thus light-emitting efficiency is improved. DETAILED DESCRIPTION - Composite material comprises silica-coated quantum dots (11), and graphene nano-sheets (13) bound to the surface of the silica-coated quantum dots, where the silica-coated quantum dots include quantum dots and silica layer (12) is coated on the surface of the quantum dots, and the graphene nano-sheets and the silica layer are bound by (O-)3Si-R1-NHCO-R3-CONH-R2-Si(O-)3 or (O-)3Si-R4-SCH2CH2-R5-Si(O-)3. R1, R2, R4 and R5 = 2-20C hydrocarbyl group or 2-20C hydrocarbyl derivative; and R3 = 2-20C hydrocarbyl group, 2-20C hydrocarbyl derivative, 6-20C aryl or 6-20C aryl derivative. An INDEPENDENT CLAIM is also included for preparing composite material, comprising either providing silica coated quantum dots, then combining surface of the silica layer with first modifier, then providing graphene nano-sheets, combining surface of the graphene nano-sheets with a second modifier, mixing the graphene nano-sheets with second modifier on the surface and the silica-coated quantum dots with first modifier on the surface such that the silica-coated quantum dots and the graphene nano-sheets (O-)3Si-R1-NHCO-R3-CONH-R2-Si(O-)3 formed by the reaction between the first modifier and the second modifier to obtain composite material, where when the first modifier is (O-)3Si-R1-NH2, then the second modifier is (O-)3Si-R2-NHCO-R3-COOH, when the first modifier is (O-)3Si-R1-NHCO-R3-COOH, then the second modifier is (O-)3Si-R2-NH2; or providing silica-coated quantum dots, then combining the surface of the silica layer with third modifier, providing graphene nano-sheets and combining surface of the graphene nano-sheets with fourth modifier, then mixing the graphene nano-sheets with the fourth modifier on the surface and the silica-coated quantum dots with the third modifier on the surface, then reacting silica coated quantum dots and the graphene nano-sheets by the third modifier and the fourth modifier to form (O-)3Si-R4-SCH2CH2-R5-Si(O-)3 to obtain composite material, where the third modifier is (O-)3Si-R4-SH or (O-)3Si-R5-CH2=CH2, the fourth modifier is (O-)3Si-R5-CH2=CH2 or (O-)3Si-R4-SH, when the third modifier is (O-)3Si-R4-SH, then the fourth modifier is (O-)3Si-R5-CH2=CH2, when the third modifier is (O-)3Si-R5-CH2=CH2, and then the fourth modifier is (O-)3Si-R4-SH. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the composite material. Quantum dot (11) Silica layer (12) Graphene nano-sheets (13)