▎ 摘　　要

NOVELTY - The composite piezoelectric material has an organic piezoelectric phase, an inorganic piezoelectric phase particle and a doped phase. The inorganic piezoelectric phase particle is used as conductive phase inorganic piezoelectric phase heterojunction particle. The doped phase forms hydrogen bond with the polar atom in the organic piezoelectric phase. The conductive phase inorganic piezoelectric heterojunction particles are synthesized by optical field reduction method or electro-deposition method. The doped phase is selected from graphene oxide, hydroxylated or carboxylated single wall or multi-wall carbon nano tube. USE - Composite piezoelectric material for use in self-focusing type composite film of ultrasonic transducer (all claimed). ADVANTAGE - The composite piezoelectric material has high voltage electrical property and high electromechanical coupling coefficient. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a preparation method of the composite piezoelectric material, (2) a preparation method of self-focusing type composite piezoelectric thin film, (3) a preparation method of ultrasonic transducer. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the semi-spherical mold structure. Semi-spherical container (1) Spaced fixed parallel gap (2) MAtching hemisphere (3)