Synthesis of Ni-doped ZnO nanostructures by low-temperature wet chemical method and their enhanced field emission properties

In this study, we report the enhancement in field emission (FE) properties of ZnO nanostructure by Ni doping at the base pressure of ~1 x 10-8 mbar, which were grown by the simple wet chemical process. ZnO nanostructure shows single crystalline wurtzite structure up to Ni 10% doping. FESEM represents change in the nanostructure morphology from thick nanoneedles to nanoflakes via thin nanorods with increase in Ni doped ZnO. The turn-on field required to draw a field emission (FE) current density at 1{\mu}A/cm2 is found to be 2.5, 2.3, 1.8 and 1.7 V/{\mu}m for ZnO(Ni0%), ZnO(Ni5%), ZnO(Ni7.5%) and ZnO(Ni10%), respectively.