Heterogeneously integrated acoustoelectric amplifiers

An acoustoelectric amplifier and a number of corresponding devices are disclosed, along with methods for making the same. The acoustoelectric amplifier employs wafer-scale bonding to heterogeneously integrate an epitaxial III-V semiconductor stack and a piezoelectric layer. To increase the acoustic gain with low power dissipation, the electromechanical coupling coefficient (k2) of the piezoelectric layer should be high to increase the acoustoelectric interaction strength. The semiconductor mobility should be high to reduce the voltage required to increase the carrier drift velocity. The conductivity-thickness product should be low to prevent screening of the acoustoelectric interaction. The acoustoelectric amplifier or its corresponding material structure may be used to form circulators, isolators, oscillators, mixers, and correlators, while interconnecting waveguides may be formed of the piezoelectric layer or the semiconductor stack. An exemplary piezoelectric layer is formed of LiNbO3, while an exemplary semiconductor stack is formed of InGaAs/InP.