▎ 摘　　要

NOVELTY - Preparation of composite material involves dissolving graphene oxide in first solvent to obtain first solution, dissolving precursor salt containing titanium element in second solvent to obtain second solution, adding first solution into second solution, leaving and processing to obtain precursor solution, and calcining precursor solution. USE - Preparation of composite material used for photovoltaic device and light emitting diode (all claimed). ADVANTAGE - The method enables effectively reducing surface hanging bond of titanium dioxide nanoparticles, utilizing surface defect as electron transport layer of quantum dot device, and promoting migration rate of carrier in device, so as to improve performance of the device. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) photovoltaic device, which comprises oppositely set cathode and anode, a quantum dot photosensitization absorption layer located between the cathode and anode, and an electronic transmission layer between the cathode and quantum dot photosensitization absorption layer, where the material for forming electronic transmission layer comprises the composite material; and (2) light emitting diode.