1. A display device comprising a display layer and a base layer under the display layer, wherein the base layer comprises:a substrate having a first conductivity type;
a well region, positioned in a portion of a side of the substrate facing towards the display layer, the well region having a second conductivity type opposite to the first conductivity type; and
an ultrasonic receiver formed in the well region, wherein the ultrasonic receiver comprises:
a first bottom electrode facing towards the substrate, the first bottom electrode comprising a first semiconductor region formed in the well region, and the first semiconductor region having the first conductivity type;
a first top electrode facing towards the display layer; and
a first piezoelectric layer, formed between the first bottom electrode and the first top electrode.