Oxygen annealing effect on field-emission characteristics of hydrothermally synthesized Al-doped ZnO nanowires

Abstract

Al-doped ZnO (AZO) nanowires (NWs) were synthesized using low-temperature hydrothermal growth to investigate field emission (FE) characteristics. The intensity ratio of NBE peak to DLE peak (R = I-NBE/I-DLE) increases and the half-maximum of NBE peaks (FWHMNBE) decreases with the Al contents. Experimental results reveal the FE characteristics of AZO NWs are functions of Al content. Moreover, the larger R value and the smaller FWHMNBE are found as the oxygen annealing temperature increases. The hydrothermal AZO NWs annealed in oxygen ambience with an appropriate temperature (i.e. 300-500 degrees C) can demonstrate the further improved FE properties (i.e. the turn-on field of 1.70 V/mu m (at 1 mu A/cm(2)), threshold field of 2.92 V/mu m (at 1 mA/cm(2)), and beta of 4547). (C) 2012 Elsevier B.V. All rights reserved.