Application Of Nano Silver Particles-Zinc Oxide Nanorods Composites In Dye-Sensitized Solar Cells

Due to the depletion of energy and environmental pollution,there has been increasing interest in solar cell research over the past few decades.In addition to solar cells based on p-n junctions,many new types of solar cells,such as dye-sensitized solar cells(DSSCs)and quantum dot-sensitized solar cells,have also attracted widespread attention.Among them,DSSCs have become promising candidates due to their low manufacturing cost and simple production methods.The DSSCs flow through the externally generated dye electrons through the external circuit to the counter electrode,oxidizing the electrolyte and completing the cycle.Zinc oxide(ZnO)can be said to be the most studied photoanode material except titanium dioxide,which has attracted much attention due to its high electron mobility and various nanostructured forms.ZnO is an important wide bandgap semiconductor material with a band gap of about 3.37 eV at room temperature.Compared to the exciton binding energy of other semiconductor materials(such as ZnSe(22meV)and GaN(25 meV)),zinc oxide has 60 meV,which is far greater than the exciton binding energy of other semiconductors,making zinc oxide more High luminous efficiency and better application potential.In addition,ZnO,as a typical representative of the third-generation semiconductor nanomaterials,has the advantages of low price,abundant source,easy preparation,and good chemical stability,which makes it more widely used.Nano-zinc oxide has a small volume and a large specific surface area(usually in the range of 1 to 100 nm),which makes it have surface effects and quantum size effects,and is superior to ordinary ZnO.The characteristics of electricity and optics make them have broader application prospects in the fields of sensors and solar cells.In this experiment,a zinc oxide seed layer was prepared on a glass substrate by spin coating,and a nanorod array grown under different conditions was prepared by hydrothermal reaction.The Ag nanoparticles are then obtained by reduction under different conditions on a zinc oxide nanorod array using photodeposition.Finally,the optimal film is used for the preparation and measurement of solar cells.(1)Preparation and Micromorphology of ZnO Nanorod ArraysThe ZnO thin films were prepared by the combination of spin coating and hydrothermal methods.The effects of different conditions on the morphology of ZnO nanorod arrays in hydrothermal reaction were investigated by SEM and XRD.The various growth conditions of zinc oxide nanorods were systematically analyzed.The experimental results show that when the seed layer solution concentration is 0.1 mol/l,the hydrothermal concentration is 50 mM and the growth time is 9 h,it is the best process condition.The ZnO nanorod arrays prepared under these conditions have suitable diameter and height data under the observation of scanning electron microscope,that is,the most ideal conditions for the growth of zinc oxide nanorod arrays.(2)Preparation and testing of nano-Ag-ZnO thin filmsThe ZnO nanorod array was prepared by spin coating and hydrothermal method in the previous step,and then Ag particles were reduced on the ZnO nanorods by photodeposition to obtain Ag-ZnO thin films.A comparative design experiment was conducted to investigate the effect of silver nitrate concentration and deposition time on Ag-ZnO thin films.The experimental results show that as the deposition time and deposition concentration increase,the coverage of Ag NPs(Nanoparticle)will increase.The deposition concentration mainly affects the amount of Ag NPs,and the deposition time mainly affects the particle size of Ag NPs.(3)Preparation and properties of Ag-ZnO thin film solar cellsAccording to the method in the first two steps,the obtained silver-zinc oxide film was further subjected to dye sensitization to prepare a solar cell,and the performance test was performed on the basis of the above.In this test,a solar cell with FF = 0.468 and a conversion efficiency of 0.639% was prepared.The current Isc was increased from 1.84 mA to 2.26 mA by the addition of silver particles.The conversion efficiency was increased from 0.554% to 0.639%,this is because the local surface plasmon resonance effect leads to an increase in light absorption,and the increase in specific surface area results in a combined effect of more dye adsorption.