Controlled Hetero-Architectures of Au-Nanoparticles-Decorated ZnO Nanowires for Enhanced Field Electron Emission Displays

Abstract

The spitzer shaped pointed ZnO nanowires of diameter 120 nm and length ∼5-6 μm synthesized via hydrothermal techniques were decorated with Au nanoparticles of diameter < 20 nm along their textural boundaries. The turn-on field (Eon) of 1.56 V/μm required to draw current density of 10 μA/cm2 from ZnO nanowires was reduced further to 0.96 V/μm after controlled decoration of Au nanoparticle, is significantly lower than pristine/doped ZnO nanostructures, Ag@ZnO, Au@ZnO, Au@CuO, and MoS2@TiO2 heterostructure based field emission (FE) devices. The orthodoxy test confirmed the feasibility of field-enhancement factor (βFE) of 4477 for Au/ZnO/ITO emitters. The enhanced FE behavior are attributed to pointed nanotips, individual dispersion of Au nanoparticles along the textural boundaries of ZnO nanowires, and enhanced energy well formation at their interface. Moreover, the density of state increases enormously due to the hetero-structured interface of Au@ZnO and a significant amount of electrons from both Au and ZnO contribute for enhanced emission current density (2.1 mA/cm2 @ 1.92 V/μm), and greatly stable electron emission. Our experiments suggest that the tunable hetero-architectures of Au nanoparticles@ZnO nanowires hold the promises for applications in display screens and intense electron source. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim