Techniques described herein address these and other issues by providing an under-display sensor capable of providing fingerprint scanning over an entire display using optical and/or ultrasonic means. To do so, the sensor comprises an array of pixels, where each can pixel comprises a piezoelectric sensor element and a diode capable of being used as a photodetector during a light-sensing mode, and as a peak detector during a pressure-sensing mode. The sensor may further comprise a piezoelectric layer and one or more electrodes, which can generate a pressure wave during the pressure sensing mode.