Piezoelectric sensor and manufacturing method thereof, method for recognizing fingerprint, and electronic device

A method for recognizing a fingerprint, comprising:

• exciting a piezoelectric sensor by an excitation source to generate ultrasonic waves;
• and
• receiving the ultrasonic waves reflected by a finger by the piezoelectric sensor and converting the ultrasonic waves that are received into electrical signals to realize fingerprint recognition,
• wherein the piezoelectric sensor comprises:
• a first electrode layer and a second electrode layer which are opposite to each other;
• and
• a piezoelectric layer which is between the first electrode layer and the second electrode layer and comprises a plurality of piezoelectric units arranged at intervals and an insulation layer between adjacent piezoelectric units of the plurality of piezoelectric units,
• wherein the first electrode layer comprises a plurality of sub-electrodes corresponding to the plurality of piezoelectric units;
• or
• the second electrode layer comprises a plurality of sub-electrodes corresponding to the plurality of piezoelectric units;
• or
• both the first electrode layer and the second electrode layer comprise a plurality of sub-electrodes corresponding to the plurality of piezoelectric units,
• wherein Young's modulus of a material of the insulation layer is smaller than Young's modulus of a material of the piezoelectric unit.

A method of manufacturing a piezoelectric sensor, comprising:

• forming a second electrode layer on a base substrate;
• forming a plurality of piezoelectric units arranged at intervals and an insulation layer between adjacent piezoelectric units of the plurality of piezoelectric units on the second electrode layer;
• and
• forming a first electrode layer on a side of the piezoelectric units away from the second electrode layer,
• wherein the first electrode layer comprises a plurality of sub-electrodes corresponding to the plurality of piezoelectric units;
• or
• the second electrode layer comprises a plurality of sub-electrodes corresponding to the plurality of piezoelectric units;
• or
• both the first electrode layer and the second electrode layer comprise a plurality of sub-electrodes corresponding to the plurality of piezoelectric units,
• wherein Young's modulus of a material of the insulation layer is smaller than Young's modulus of a material of the piezoelectric unit.