Investigation On The Preparation And Properties Of One-Dimensional ZnO Nanomaterials By Water Bath Method

ZnO is an important wide band semiconductor with a band gap of 3.37eV and exciton banding energy of 60meV,which have extensive application for fabricating microelectronics and optoelectronics devices.The more considerable attention on ZnO nanomaterials because of its special electric,optical,magnetic properties.In this paper,the aqueous solution of zinc nitrate(Zn(NO₃)₂) reacted with the aqueous solution of equimolar methenamine ((CH₂)₆N₄) by using water bath method.ZnO nanostructure with different morphologies were prepared on Si substrates and surface treated Si substrates.With the different growth condition, ZnO nanostructure with controllable morphologies were successfully prepared.ZnO nanorods,nanorod arrays,nanoparticles, nanosheets,nanotubes were prepared by changing the concentration of solution,reaction time, reaction temperature,pH value and substrates. The ingredient,surface feature and crystal structure of the samples are characterized by XRD, SEM and EDS.The growth mechanism of ZnO nanostructure is investigated in detail.The ZnO nanorod arrays are characterized by XRD and PL spectrum.Annealing, Al³⁺ doping and Co²⁺ doping play a important role in the crystal structure and photoluminescence properties of ZnO nanorod arrays.The intensity of characteristic luminescent peaks increases after Annealing, Al³⁺ doping and Co²⁺ doping.With the increase of doping concentration, The intensity of characteristic luminescent peaks increase flrst,but then decrease. And there is a little red shift due to quantum size effect.The samples with Co²⁺ doping could more effectively improve the intensity of characteristic luminescent peaks.Their luminescence mechanisms and the reason of red-shift have been explained.These investigations provide a lot of experimental and theoretical foundations for fabricating optical devices,which based on ZnO nanorod arrays.Field emission properties are investigated on ZnO nanorod arrays,which are prepared in different concentration of solution and substrates.The shielding effect weaken between ZnO nanorods and has better electron emission properties when the concentration of solution is 0.01 mol/L.The field emission properties enhance after gilding or copperizing on Si substrates. Because it can provide more emission electrons and good conducting channel.The key factors have been discussed by SEM and facula test.Then provide some methods to enhance field emission properties.It illuminates that the ZnO nanorod arrays,which are prepared by water bath method has perfect field emission properties and can be used as field emitters.It has great development foreground in field emission application.