Polarization of ions in a crystal that has non-central symmetry, a piezoelectric potential
(piezopotential) is created in the crystal by applying a stress. For materials such as ZnO, GaN, and InN in
the wurtzite structure family, the effect of piezopotential on the transport behavior of charge carriers is
significant due to their multiple functionalities of piezoelectricity, semiconductor and photon excitation.
By utilizing the advantages offered by these properties, a few new fields have been created. Electronics
fabricated by using innercrystal piezopotential as a ‘‘gate’’ voltage to tune/control the charge transport
behavior is named piezotronics, with applications in strain/force/pressure triggered/controlled
electronicdevices, sensors and logic units. Piezo-phototronic effect is a result of three-way
couplingamong piezoelectricity, photonic excitation and semiconductor transport, which allows
tuningand controlling of electro-optical processes by strain induced piezopotential. The objective of this
review article is to introduce the fundamentals of piezotronics and piezo-phototronics and to give an
updated progress about their applications in energy science and sensors.