Fingerprint identification substrate, fingerprint identification method and display device

A fingerprint identification method using a fingerprint identification substrate, the fingerprint identification substrate comprises a base substrate, a transmitting part provided on the base substrate, a receiving part provided on the base substrate, wherein at least a portion of the transmitting part and at least a portion of the receiving part are provided in a single layer, the fingerprint identification method comprising:

• step S1, generating, by the transmitting part, an ultrasonic signal;
• step S2, receiving, by the receiving part, the ultrasonic signal reflected by a finger, converting the ultrasonic signal into an electric signal and outputting the electric signal to a fingerprint detector;
• and
• step S3, determining fingerprint information, by the fingerprint detector, according to the electric signal output from the receiving part,
• wherein the transmitting part comprises a first electrode, a first piezoelectric material layer and a second electrode provided successively in a direction away from the base substrate, and the receiving part comprises a third electrode, a second piezoelectric material layer and a fourth electrode provided successively in a direction away from the base substrate, the fingerprint identification substrate further comprises a plurality of driving signal lines, a plurality of read signal lines and a plurality of reset signal lines provided above the base substrate, the fingerprint detector comprises a rectifying diode, a first transistor, a second transistor and a third transistor, a first electrode of the rectifying diode is connected to the third electrode, a second electrode of the rectifying diode is connected to a first node, a first electrode of the first transistor is connected to a corresponding one of the read signal lines, a second electrode of the first transistor is connected to a first electrode of the second transistor, a control electrode of the first transistor is connected to the driving signal line in (N+1)th row, where N is an integer larger than or equal to 1, the first electrode of the second transistor is connected to the second electrode of the first transistor, a second electrode of the second transistor is connected to a first power supply terminal, a control electrode of the second transistor is connected to the first node, a first electrode of the third transistor is connected to a corresponding one of the reset signal lines, a second electrode of the third transistor is connected to the first node, a control electrode of the third transistor is connected to the driving signal line in Nth row, and the first node is a connection node connected to the second electrode of the third transistor, the second electrode of the rectifying diode and the control electrode of the second transistor, the step S3 comprises:
• a reset stage, inputting a high level signal to the driving signal line in Nth row, and inputting a reset signal to the reset signal line;
• a charge accumulation stage, waiting for a period of time;
• and
• a read stage, inputting a low level signal to the driving signal line in Nth row, inputting a high level signal to the driving signal in (N+1)th row, inputting a first power supply voltage to the first power supply terminal, and determining the fingerprint information by reading a potential of the first electrode of the second transistor through the read signal line.