▎ 摘　　要

NOVELTY - Nano material comprises graphene quantum dot and nitrogen oxide, the surface of the graphene quantum dot is connected with carbonyl-containing group, and surface of the nitrogen oxide is connected with hydroxy group, the nitrogen oxide is combined with graphene quantum dot through interaction between the hydroxy group and the carbonyl-containing group. USE - The nano material is useful for light-emitting film used in display device (all claimed). ADVANTAGE - The nano material: can avoids increasing the electro-excitation efficiency of graphene quantum dots, and avoids breakdown of devices due to high-energy electrons in strong electric field. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing the nano material comprising providing graphene quantum dot and nitrogen oxide, connecting surface of the graphene quantum dot with carbonyl-containing group, connecting surface of nitrogen oxide with hydroxy group, dispersing the graphene quantum dots and nitrogen oxide in solvent, combining nitrogen oxide with graphene quantum dot through interaction between hydroxy group and carbonyl containing group in solvent; (2) light-emitting film comprising nano material; and (3) display device comprising the light-emitting film