Piezoelectricity, a phenomenon known for centuries, is an effect that is about the production of electrical potential in a substance as the pressure on it changes. For wurtzite structures such as ZnO and GaN, due to the polarization of ions in a crystal that has non-central symmetry, a piezoelectric potential (piezopotential) is created in the crystal by applying a stress owing to the presence of one atomic-layer thick polarization charges at the surface/interface. Electronics fabricated by using inner-crystal piezopotential as a “gate” voltage to tune/control the charge transport behavior is named piezotronics, with applications in strain/force/pressure triggered/controlled electronic devices, sensors and logic units. Piezo-phototronic effect is a result of three-way coupling among piezoelectricity, photonic excitation and semiconductor transport, which allows tuning and controlling of electro-optical processes by strain induced piezopotential. The objective of this talk is to introduce the fundamentals of piezotronics and piezo-phototronics and to give an updated progress about their applications in human-machine interfacing, optoelectronics, sensors and chemistry (LED, solar cell, photon detectors, photon catalysis).

Dr. Zhong Lin Wang is the Director of the Beijing Institute of Nanoenergy and Nanosystems, and Regents’ Professor and Hightower Chair at Georgia Institute of Technology. Dr. Wang pioneered the nanogenerators from fundamental science to technological applications. His research on self-powered nanosystems has inspired the worldwide effort in academia and industry for studying energy for micro-nano-systems. He coined and pioneered the fields of piezotronics and piezo-phototronics for the third generation semiconductors. Among 100,000 scientists across all fields worldwide, Wang is ranked #5 in career scientific impact, #1 in Nanoscience, and #2 in Materials Science. His google scholar citation is over 280,000 with an h-index of over 256.