Influence of annealing temperature on field emission from tetrapod-shaped ZnO-whisker films obtained by screen printing

Tetrapod-shaped zinc oxide whisker-film emitters were fabricated on indium tin oxide glass substrates using a screen-printing method. The influence of annealing temperature on field emission of tetrapod-whisker ZnO-based emitters was investigated. X-ray diffraction and scanning electronic microscopy were applied to characterize the structure and the surface morphology of the deposited films. It was found that ZnO-based emitters annealed at 250 degrees C have the best field emission properties with the lowest turn-on field of 2.6 V/mu m at a current density of 1 mu A/cm(2), the lowest threshold field of 5.2 V/mu m at a current density of 1 mA/cm(2) and high field emission enhancement factor of 4129. Moreover, films with homogeneous, fine and dense light spots with low emission current fluctuation of 1.7% were obtained from samples annealed at 250 degrees C. (C) 2011 Elsevier Ltd. All rights reserved.