▎ 摘　　要

NOVELTY - A graphene-yttrium fluoride up-conversion fluorescent powder composite material comprises ytterbium-erbium-doped graphene, ytterbium-erbium-doped graphene-( alpha )-sodium yttrium fluoride and ytterbium-erbium-doped graphene-( beta )-sodium yttrium fluoride. USE - Graphene-yttrium fluoride up-conversion fluorescent powder composite material (claimed). ADVANTAGE - The graphene-yttrium fluoride up-conversion fluorescent powder composite material has excellent up-conversion fluorescence property, and is environmentally-friendly and prepared by a simple process. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of graphene-yttrium fluoride up-conversion fluorescent powder composite material, which involves using graphite powder as a raw material to prepare graphite oxide by Hummer method, performing ultrasonic dispersion of 5-85 mg graphite oxide and 24-60 mL water, adding 0.05-1 mmol yttrium nitrate, ytterbium nitrate and erbium nitrate and 0.02-0.5 g sodium fluoride, stirring for 5-10 minutes, transferring the resultant mixture into a 100 mL reactor, reacting at 200-240 degrees C for 4-24 hours, naturally cooling to room temperature, centrifuging and washing the resultant product with deionized water.