▎ 摘　　要

NOVELTY - The method involves dissolving zinc nitrate in ultrapure water to obtain a zinc nitrate solution with a concentration of 0.04-0.07mol/l. The aqueous ammonia that completely react zinc nitrate into the zinc nitrate solution is added, and the reaction I performed with magnetic stirring to obtain a zinc hydroxide mixed solution. The graphene film is transferred to a silicon wafer substrate (1) using wet technology, and placed in the zinc hydroxide mixed solution, deposited in a water bath, and separated to obtain a pre-sample. A front sample is preheated for 0.5h-3h. The zinc oxide/graphene sample is placed in the precursor mixed solution using the electrochemical deposition method, and a lead sulfide film is deposited on the zinc oxide/graphene sample, where the precursor mixed solution is a mixed solution of lead acetate, disodium edetate, and sodium sulfide. A composite material of lead sulfide (3)/zinc oxide (4)/graphene (2) is obtained after the deposition is completed. USE - Preparation method of composite material for photodetection. ADVANTAGE - The zinc oxide quantum dots are introduced on the graphene film to produce defects that promote the growth of crystal nuclei, and the deposition of the lead sulfide film is facilitated. The zinc oxide as a wide band gap semiconductor material has excellent light transmittance and electrical properties. The formed heterojunction effectively improves the gain and responsivity of photodetection. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram illustrating the zinc oxide or graphene or lead sulfide composite material made on silicon wafer substrate. Silicon wafer substrate (1) Graphene (2) Lead sulfide (3) Zinc oxide (4)