Fabrication And Characterization Of Zinc Oxide And ZnO-Ag Nanostructures And Their Applications In Photoelectronic Devices

In our work, we fabricated ZnO nanostructures and discussed their applicationsin photoeletronic devices and photocatalytic anodes. As wide band gap semiconductor,ZnO has advanced photo and electronic properties, and its nanostructures presentdiversity. Here, the manuscript consists of three part, they are ZnO nanostructuresfabrication, their applications in LED devices and photocatalytic anode, respectively.(1) ZnO nanostructures fabrication. In our work, ZnO nanostructures werefabricated by hydrothermal method. To order to understand the growth mechanism,stirring time and addictive content were discussed in detail in the manuscript,respectively. It can be found that the surface morphology of ZnO is transformed fromnanoflower to nanowire as increasing the stirring time of the precursor solution. Onthe premise of the other conditions unchanged, ammonia addictive content was variedto discuss surface morphology of ZnO nanostructures. As increasing ammonia contentin the precursor solution, the morphology of ZnO was changed from irregular shape tohexagonal nanosheet, and at last to nanowire or nanorod. In this work, ZnOnanostructures can be achieved controllable growth with a simple method, and thegrowth mechanism has been discussed systematically.(2) Applications in LED devices. In this part, ZnO nanostrucutres were adoptedas hole or electron transport layer in LED devices. Firstly, Ag was doped in ZnOnanowires, which is combined with organic n-type materials to form pn junction.Secondly, ZnO nanoparticles film was used as electron transport layer in all-inorganicquantum dot LEDs. To improve the performance of the device, NiO hole transportlayer was optimized by varying its thickness. At last, ZnO nanoparticle film was usedin inorganic-organic hybrid quantum dot LEDs, in which TCTA was doped inpoly-TPD to form a composite hole transport layer to improve the performance. Toexplain the mechanism of electroluminescence, we compared experimental results andtheoretical analysis.(3) Applications in photocatalysis. Here, we mainly discuss ZnO nanostrucutresapplication in photocatalytic water splitting for hydrogen generation. To improvephotocatalytic performance, ZnO nanowires were modified with noble metallic Agnanoparticles. The effects of Ag nanoparticles with different structures on theperformance of ZnO nanowires have been systematically discussed. Moreover, to achieve effective hydrogen generation, Ag nanoparticles were introduced a traditionalcore-shell structure ZnO/CdS. The three component anode ZnO/Ag/CdS showssignificantly enhance light absorption, improved photocurrent and rapid light response.Interestingly, the composite anode showed enhance photocorrosion resistance, andthere is no obvious photocorrosion or decomposition even after6hours reaction.These advanced properties facilitate the composite ZnO/Ag/CdS to be an effectiveanode for hydrogen generation. This composite anode generated35ml hydrogenwhen the anode was driven by0.4V.Through the simple discussion above, we can understand ZnO nanostructuresgrowth mechanism, which is the precondition for the subsequent experiment. In ourwork, ZnO nanostructures were adopted in LED and photocatalytic applications, andthe performance of devices or anodes can be greatly improved. The work reportedhere is suggestive and has some significance.