▎ 摘　　要

NOVELTY - Composite material comprises graphene oxide and nickel oxide nanoparticles that are bonded to the surface of the graphene oxide, where the nickel oxide nanoparticles are connected to the surface of the graphene oxide through dopamine. The amino group of the dopamine is connected to the graphene oxide, and the hydroxyl group of the dopamine is connected to the nickel oxide nanoparticles. USE - Composite material used as hole transport material for quantum dot light emitting diodes (all claimed). ADVANTAGE - The composite material has good conductivity and stability, reduces the recombination of electrons and holes in the light-emitting layer, improves the hole transport efficiency, and improves the luminous efficiency and display performance of the device. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a method for preparing composite material, which involves providing dopamine and graphene oxide, dissolving the dopamine and graphene oxide in a first solvent, and performing a first heating treatment to obtain graphene oxide with dopamine bound on the surface, dissolving the graphene oxide and nickel oxide with dopamine bound on the surface in a second solvent, and performing a second heating treatment to obtain a precursor solution, and depositing the precursor solution on a substrate and performing an annealing treatment to obtain the composite material; and (2) a quantum dot light-emitting diode, which comprises an anode, a cathode and a quantum dot light-emitting layer that is arranged between the anode and the cathode.