Capacitive piezotronics

Interface engineering by polarization derives a plethora of distinctive phenomena. Most of them focus on modulation of barrier height for controlling carrier transport of direct-current electronics. However, modulating interface width under alternating-current settings and its resultant effects have not been explored. Here, we report the capacitive piezotronics, which utilizes piezoelectric polarization to control the interface width of heterostructures and modulate junction capacitance at high frequency. The built-in electric potential and the interface width can be reversibly tuned with amplitude as high as 0.11 V and 10.5 nm, which presents a high strain sensitivity ( > 110 fF/mbar), and surpasses that of commercial capacitive pressure sensors ( ~ 0.1-0.7 fF/mbar). It possesses a capacity of mechanically tuning transmission signal of communication systems with an amplitude > 11 kHz, and substantially improving the filtering characteristics particularly for high frequency noise ( > 300 kHz). The strain-tuned alternating-current electronics offer a distinctive approach for high quality communication.