Synthesis and field emission properties of ZnCdO hollow micro-nano spheres

The ZnCdO hollow micro-nano spheres have been achieved on the Si substrates without any catalysts using a simple thermal evaporation method. X-ray diffraction spectra confirm that the sample is a hexagonal wurtzite structure, and a little Cd doping would not change the crystal structures of ZnO. The growth mechanism of the ZnCdO hollow micro-nano spheres is deduced in detail. The PL spectra illustrate that Cd doping could induce the red-shift of optical band gap. Field emission measurements show a low turn-on field of similar to 1.86V/mu m at a current density of 1 mu A/cm(2). The emission current density reached 1 mA/cm(2) at an applied field of similar to 9.26 V/mu m. (C) 2008 Published by Elsevier B.V.