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

Abstract

Abstract: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 1µA/cm 2 is found to be 2.5, 2.3, 1.8 and 1.7 V/µm for ZnO(Ni0%), ZnO(Ni5%), ZnO(Ni7.5%) and ZnO(Ni10%), respectively. The highest current density of ~870 µA/cm 2 is achievable, which drawn at an applied field of 3.1 V/µm for Ni 10%

Controllable Ag nanoparticle coated ZnO nanorod arrays on an alloy substrate with enhanced field emission performance

“…Especially, ZNAs or ZNWs has attracted more attentions due to advantages of controllable morphology, environment-friendship, low cost, and feasibility of large scale growth. 9,10 In the past few years, great efforts have been made to improve the FE performances of ZNAs or ZNWs, such as doping, [11][12][13] coating with other materials, [14][15][16] or growing on the conducting substrate. 17,18 Among these methods, one of the most effective strategies is to construct ZnO based composite FE materials, which can either enhance the emission sites by forming a rough surface, or improve its conductivity due to the synergistic effect between different materials.…”

Comparison of Effect of Nickel Concentration on Crystallographic Structure and Morphology of Zinc Oxide Nanopowders

“…It is known that the possible growth mechanism of the nanomaterials can be described on basis of chemical reactions and nucleation process (Rana et al, 2016). The possible chemical reactions, which are responsible for the growth on Ni doped ZnO nanostructure were already given in (Rana et al, 2016). The XRD diffraction patterns of the pure ZnO and Ni doped ZnO nanopowders synthesized by sol-gel technique are shown in Fig.…”

“…There is no linear correlation between concentration of Ni and crystallite size of the samples. This situation was concluded in the literature (Rana et al, 2016) that the reason might be dissimilar conditions for different doping concentration as well as a lot of distortions in the host ZnO lattice that turns out lattice relaxation or compression in the host lattice because of the vacancy and/or interstitial defect already existing in the host lattice. The sample with x=0.05 having the highest crystallite size showing the smallest dislocation density and the smallest strain.…”

“…There are also some other studies about Ni doped ZnO using sol-gel method (Srinet et al, 2013;Liu et al, 2014), low temperature hydrothermal method (Xu et al, 2016), low temperature wet chemical method (Rana et al, 2016) and about shape controlled magnetic nanoplatelets of Ni doped ZnO (Jadhav et al, 2016). The crystallographic structure and morphology of Ni doped ZnO, and further physical properties, are affected by preparation technique and external conditions such as concentration of Ni, reaction temperature, reaction time, annealing temperature, pH value, starting precursors, solution concentration, and etc.…”

Enhanced ferromagnetism of ZnO@Co/Ni hybrid core@shell nanowires grown by electrochemical deposition method

“…ZnO NWs with Co/Ni doping have been studied in many different applications, e.g. photo-catalysis, [14][15][16][17][18] spintronics and optoelectronics devices, [19][20][21][22][23][24][25][26][27][28] or sensors. 29,30 Recently, the researchers have started investigating the property of the Co/Ni coated ZnO NWs in core@shell structure.…”