Associate Professor,Optics and Photonics (Group Chair)
Georgia Tech, USA
Title: Piezo-Phototronic effect in ZnO nanowire LEDs
Authors: Ying Liu, Simiao Niu, Qing Yang, Benjamin Klein, Yu Sheng Zhou, Zhong Lin Wang
The piezoelectric effect in polar non-centrosymmetric crystals such as ZnO leads to induced surface and volumetric charge when the crystal is strained. This effect alters the spatial dependence of the band edge energies of a semiconductor device, and can be utilized to strongly influence the operation of the device. When this is used to influence the electronic properties of the device, it is referred to as the piezotronic effect; when it is used to influence both the electronic properties and the light absorption or emission it is referred to as the piezo-phototronic effect. Two-dimensional finite-element simulation of strained ZnO nanowire LEDs has been used to explore the experimentally observed piezo-photronic enhancement of light emission efficiency. In this talk, I will explain the theory of the piezo-phototronic effect and present some experimental and simulation results to quantify it.
Benjamin Klein received is B.S. and M.S. in Electrical Engineering from the University of Wisconsin-Madison in 1994 and 1995 respectively, and his Ph.D. in Electrical Engineering from the University of Illinois at Urbana-Champaign in 2000.
From 2000-2003 he served as a postdoctoral Fellow at the National Institute of Standards and Technology in Boulder, Colorado. Since 2003 he has been on the faculty of the School of Electrical and Computer Engineering at the Georgia Institute of Technology.
His research involves the theory, modeling, and design of optical, electronic, and optoelectronic devices.