Piezotronics

[1] The fundamental principle of piezotronics was introduced by Prof. Zhong Lin Wang at Georgia Institute of Technology in 2007.

Piezotronics is likely to have important applications in sensor, human-silicon technology interfacing, MEMS, nanorobotics and active flexible electronics.

Due to the non-central symmetry in materials such as the wurtzite structured ZnO, GaN and InN, a piezopotential is created in the crystal by applying a stress.

Owing to the simultaneous possession of piezoelectricity and semiconductor properties, the piezopotential created in the crystal has a strong effect on the carrier transport process.

The introduced piezoelectric field is perpendicular to electron transport direction, just like applying a gate voltage in the traditional field-effect transistor.

Working mechanism for piezotronic devices with two ends fixed with electrodes on a flexible substrate. This asymmetric tuning of the Schottky barrier height is the piezotronic effect.
Working mechanism for piezoelectric devices with one end of the piezoelectric material is fixed. The induced piezopotential distribution is similar to the applied gate voltage in a traditional field-effect transistor , as shown in (b).
Schematic diagram showing the three-way coupling among piezoelectricity , photoexcitation and semiconductor .