▎ 摘　　要

NOVELTY - Preparation of composite material involves providing graphene oxide and molybdenum oxide solution, adding graphene oxide to molybdenum oxide solution, obtaining a precursor solution, and annealing. USE - Preparation of composite material used for hole transport layer of quantum dot light-emitting diode (all claimed). ADVANTAGE - The method enables preparation of composite material having excellent hole transporting material. The quantum dot light-emitting diode using the composite material has reduced contact resistance. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) composite material, which comprises molybdenum oxide nanoparticles and graphene oxide dispersed between the nanoparticles; and (2) quantum dot light-emitting diode, which comprises a cathode, an anode and a quantum dot light-emitting layer arranged between the cathode and the anode. The quantum dot light-emitting diode further has a hole transport layer arranged between the anode and the quantum dot light-emitting layer. The hole transport layer contains the composite material.