title: Largely enhanced efficiency in ZnO nanowire/p-polymer hybridized inorganic/organic ultraviolet light-emitting diode by piezo-phototronic effect.
abstract: ZnO nanowire inorganic/organic hybrid ultraviolet (UV) light-emitting diodes (LEDs) have attracted considerable attention as they not only combine the high flexibility of polymers with the structural and chemical stability of inorganic nanostructures but also have a higher light extraction efficiency than thin film structures. However, up to date, the external quantum efficiency of UV LED based on ZnO nanostructures has been limited by a lack of efficient methods to achieve a balance between electron contributed current and hole contributed current that reduces the nonradiative recombination at interface. Here we demonstrate that the piezo-phototronic effect can largely enhance the efficiency of a hybridized inorganic/organic LED made of a ZnO nanowire/p-polymer structure, by trimming the electron current to match the hole current and increasing the localized hole density near the interface through a carrier channel created by piezoelectric polarization charges on the ZnO side. The external efficiency of the hybrid LED was enhanced by at least a factor of 2 after applying a proper strain, reaching 5.92%. This study offers a new concept for increasing organic LED efficiency and has a great potential for a wide variety of high-performance flexible optoelectronic devices.
authors: School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, USA.
authors: Qing
authors: Q
authors: Yang
authors: Ying
authors: Y
authors: Liu
authors: Caofeng
authors: C
authors: Pan
authors: Jun
authors: J
authors: Chen
authors: Xiaonan
authors: X
authors: Wen
authors: Zhong Lin
authors: ZL
authors: Wang
mesh_terms: D055664:Electrochemical Techniques; D053770:Nanowires / Q000737:chemistry*; D055668:Photochemical Processes; D017785:Photons; D011108:Polymers / Q000737:chemistry*; D014466:Ultraviolet Rays; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D011108:Polymers; D015034:Zinc Oxide