▎ 摘　　要

NOVELTY - Transparent piezoelectric film comprises a porous cellulose-based polymer and composite heterojunction particles loaded in the pores of the porous cellulose-based polymer, an organic piezoelectric phase, and a conductive phase. The porous cellulose-based polymer is chemically bonded to the organic piezoelectric phase, and the composite heterojunction particles are chemical heterojunction formed between conductive particles and transparent inorganic piezoelectric phase particles. USE - The transparent piezoelectric film is useful for preparing ultrasonic transducer, which is useful in photoacoustic imaging. ADVANTAGE - The transparent piezoelectric film has good tensile, transparent, piezo-electric performance and acoustic characteristics. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: preparation method of the transparent piezoelectric films, comprising providing composite heterojunction particles and porous cellulose-based polymers, dissolving the organic piezoelectric phase in an organic solvent to obtain mixed solution, adding a conductive phase into the mixed solution, and mixing uniformly to obtain first composite solution, adding the composite heterojunction particles to the first composite solution, and mixing uniformly to obtain second composite solution, injecting or evenly coating the second composite solution in the pores of the porous cellulose-based polymer, subjecting to hot pressing, and curing to obtain transparent piezoelectric film; an ultrasonic transducer, comprising transparent piezoelectric film, and electrode layers compounded on two opposite surfaces of the transparent piezoelectric film, and each electrode layer is provided with tabs, where the electrode layer is a stretchable transparent electrode layer; and preparation method of ultrasonic transducer, comprising respectively compounding stretchable transparent electrode layers on two opposite surfaces of the transparent piezoelectric film to form sandwich structure, polarizing the sandwich structure, drawing the tabs from the stretchable transparent electrode layer to obtain ultrasonic transducer.