Generation of picosecond acoustic pulses using a p-n junction with piezoelectric effects

Abstract

We demonstrate the generation of picosecond acoustic pulses using a piezoelectric-semiconductor-based p-n junction structure. This p-n junction picosecond ultrasonic experiment confirms that the piezoelectric effect dominates the thermal expansion and deformation-potential coupling in the generation of picosecond acoustic pulses. The characteristics of the p-n initiated acoustic pulses are determined by the width and the field strength inside the depletion region. Our study indicates the future possibility to electrically control the acoustic pulse characteristics if we could apply an external bias to modulate the depletion region width.