Synthesis of Te-doped ZnO nanowires with promising field emission behavior

Abstract

In the current study, a successful synthesis of ZnO nanowire films doped with Te was performed through electrodeposition on the zinc foil followed by annealing in air for 4 hours at 400 °C. The conditions for growth were chosen as the concentrations of electrolyte and deposition time. The XRD patterns for the post-annealed samples are shown as a set of well-specified diffraction peaks relating to the ZnO wurtzite phase. The growth conditions impact the surface morphologies of the as-prepared films. Upon annealing, the ZnO nanowire formation was observed for shorter deposition times. The incorporation of Te ions into the ZnO lattice was confirmed using X-ray and Auger photoelectron spectroscopy. The diverse emission bands originating from different transition mechanisms were evaluated through photoluminescence and Raman studies. In the field emission studies, the best threshold field values, which are necessary for drawing an emission current density of ∼100 μA cm⁻², are 2.13 V μm⁻¹ for T1S1 and 2.42 V μm⁻¹ for T1S2. The post-annealed film with a lower concentration of wires shows an excellent emission current stability at the preset value of ∼10 μA over 4 hours. The results show that Te ions play a key role in controlling the morphologies, resulting in various morphologies and densities of the ZnO wires, which have different field emission features. This technique may have a potential to produce electron sources for high current density applications.