title: Progress in Piezo-Phototronic-Effect-Enhanced Light-Emitting Diodes and Pressure Imaging.
abstract: Wurtzite materials exhibit both semiconductor and piezoelectric properties under strains due to the non-central symmetric crystal structures. The three-way coupling of semiconductor properties, piezoelectric polarization and optical excitation in ZnO, GaN, CdS and other piezoelectric semiconductors leads to the emerging field of piezo-phototronics. This effect can efficiently manipulate the emission intensity of light-emitting diodes (LEDs) by utilizing the piezo-polarization charges created at the junction upon straining to modulate the energy band diagrams and the optoelectronic processes, such as generation, separation, recombination and/or transport of charge carriers. Starting from fundamental physics principles, recent progress in piezo-phototronic-effect-enhanced LEDs is reviewed; following their development from single-nanowire pressure-sensitive devices to high-resolution array matrices for pressure-distribution mapping applications. The piezo-phototronic effect provides a promising method to enhance the light emission of LEDs based on piezoelectric semiconductors through applying static strains, and may find perspective applications in various optoelectronic devices and integrated systems.
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
authors.forename: Caofeng
authors.initials: C
authors.lastname: Pan
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
authors.forename: Mengxiao
authors.initials: M
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332-0245, USA.
authors.forename: Ruomeng
authors.initials: R
authors.lastname: Yu
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332-0245, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332-0245, USA.
authors.forename: Youfan
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China.|School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332-0245, USA.
authors.forename: Zhong Lin
authors.initials: ZL
authors.lastname: Wang
keywords: light-emitting diodes; piezo-phototronic effect; pressure-distribution mapping; semiconductors