▎ 摘　　要

NOVELTY - Photodetectors, comprises sandwich structure is grown on an electrically insulating substrate and zinc oxide film/graphene/zinc oxide film from bottom to top; in the zinc oxide/graphene/zinc oxide-based sandwich structure, the zinc oxide film is stoichiometric zinc oxide or anoxic zinc oxide thin film. USE - Used as photodetectors. ADVANTAGE - The photodetectors: has strong light absorption ability, high light transmittance function, high electron mobility property, strong conductive ability property, strong signal, fast response, and high detection sensitivity. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the photodetectors based on zinc oxide/ graphene/zinc oxide based sandwich structures, comprising taking sintered zinc oxide ceramic as a target material, and growing zinc oxide film on an electrically insulating substrate in radio-frequency magnetron sputtering equipment; transferring layer of graphene on the zinc oxide film by wet transfer technique; growing layer of zinc oxide on the graphene layer by RF magnetron sputtering to obtain a zinc oxide / graphene/zinc oxide sandwich structure;planting metal electrode on the upper and lower zinc oxide films to obtain the photodetector based on the zinc oxide / graphene / zinc oxide sandwich structure; including the following steps: (i) installing sintered zinc oxide ceramic on the target in the RF magnetron sputtering equipment, and fixing cleaning substrate on the sample table; starting the mechanical pump to a low vacuum, when the system vacuum reaches 0.1Pa, opening the molecular pump until the system vacuum reaches greater than or equal to 2 x 10-4 Pa; introducing the working gas argon, first pre-sputtering for 3-10 minutes in order to remove the target surface contaminants; after the glow is stable, same gas flow into the system into the working gas oxygen and argon, adjusting the sputtering pressure to 0.3-2 Pa, sputtering target power of 60-240 W, starting sputtering deposition of zinc oxide film, and sputtering time is 20-100 minutes; (ii) throwing layer of polymethylmethacrylate on the surface of the graphene grown on the copper foil, allowing the natural air to dry for 1-2 days; dissolving the ferric chloride powder in a hydrochloric acid solution (where concentrated hydrochloric acid and water volume ratio of 1:1), and preparing into 300 ml ferric chloride solution (0.1mol/l); the growth of graphene on the copper foil by the method of floating down in ferric chloride solution, 3-5 hours after the copper foil is completely corroded, taking polyethylene terephthalate with polymethyl methacrylate graphene and placing in deionized water to wash for 5-7 times; the substrate with the zinc oxide film grown in the step (i) picks up the graphene floating on the surface of the deionized water, placing in an oven at 60 degrees C for 30-60 minutes; washing the sample with acetone for 5-7 times to remove the surface of the polymethyl methacrylate graphene to complete the transfer of the graphene layer; (iii) sintering of zinc oxide ceramic mounting target in the RF magnetron sputtering equipment, fixing step (ii) transferred graphene oxide film sample on the sample stage; starting the mechanical pump pumping at low vacuum, vacuum degree of the system reaches to 0.1 Pa, opening the molecular pump until the vacuum degree of the system reaches greater than or equal to 2x 10-4 Pa,injecting the same gas flow into the system of working gas of oxygen and argon, adjusting the sputtering air pressure is 0.3-2 Pa, the sputtering target power is 60-240 W, starting to sputter deposition of zinc oxide film, sputtering time is 20-100 minutes; and (iv) using magnetron sputtering, thermal evaporation or electron beam evaporation method in the upper and lower zinc oxide film were plated on the electrode.