Fabrication of large-area ZnO nanowire field emitter arrays by thermal oxidation for high-current application

Large-area ZnO nanowire field emitter arrays have important applications in flat-panel displays, light sources, photodetectors and X-ray sources, where it is crucial to realize a high field emission current and current density over a large-area. In this paper, large-area ZnO nanowire arrays with various array spacings were prepared by the thermal oxidation technique from patterned Zn film arrays, and their field emission properties were studied. The results show that the Zn array density is related to the nanowire length and population density. A mechanism is proposed wherein the stress-induced process and mass transport process both play key roles in the growth. Herein, ZnO nanowire arrays in a 4.7 x 4.7 cm(2) area exhibited a sufficient quantity of emission sites and diminished field screening effect and a high current of 12.9 mA with a current density of 0.58 mA/cm(2). This work provides useful guidance for optimizing ZnO nanowires and enhancing field emission current performance for large-area ZnO nanowire field emission devices.