Study On The Performance Enhancement In Dye-sensitized Solar Cells By Metal Nanoparticles

With the rapid development of society,there is no doubt about the urgent need for replacing traditional fossil fuel resources with alternative renewable energy resources in order to satisfy the ever-increasing worldwide energy demand.The field of photovoltaics is of great interest among renewable energy resources because of the abundant availability of solar energy over most of the planet.To date,the field of photovoltaics is almost exclusively dominated by silicon solar cell technology,which offers efficient sunlight-to-electricity conversion,but suffers from steep production costs because of the need for high purity silicon.Hence dye-sensitized solar cells(DSCs)have attracted extensive attention as a promising alternative to traditional silicon-based photovoltaic devices due to its relatively simple fabrication methodology and high photoelectric conversion efficiency.In this paper,a series of different amounts of metal nanoparticles were incorporated into conventional TiO₂ nanocrystalline films to form the composite photoanodes for the DSCs.The influence of the metal nanoparticles on the performance of the DSCs and the mechanisms of their effects were investigated.A series of TiO₂ nanocomposite photoanodes with different amounts of Au nanocubes are prepared by a ball milling method and applied to assemble a series of dye-sensitized solar cells(DSCs).The influences of the Au nanocubes on the performance of the photoanode and dye-sensitized solar cells were investigated.Studies demonstrated the optimal properties with the short-circuit current density(J_sc)of 15.32mA·cm^-2,and the photoelectric conversion efficiency(PCE)of 6.708%are obtained in a DSCs with 0.8%Au nanocubes content,increasing significantly by 14.47%and12%in comparison with those of the DSCs with pure TiO₂ photoanode.The significant improvements in the properties of the optimal DSCs are mainly attributed to the increase of the light-absorption ability of the dye due to the localized surface plasmon resonance of Au nanocubes in composite photoanode.On the basis of optimizing the performance of dye-sensitized solar cells by Au nanocubes,the local surface plasma performance of bimetallic composite nanostructures was studied,and the experimental scheme of Au@Ag@SiO₂ core-shell nanocubes was designed.Uniform monodisperse Au nanocubes were prepared by seed growth method,and then silver nitrate was reduced by ascorbic acid to prepare Au@Ag core-shell nanocubes.In order to prevent metal nanoparticles from being corroded due to contact with electrolytes and improve the stability of Au@Ag core-shell nanocubes structure,SiO₂ shell coating was carried out on the outermost layer through hydrolysis reaction of tetraethyl silicate under weak alkaline condition.Studies have shown that the prepared Au@Ag@SiO₂ core-shell nanocubes changed the local surface plasmon resonance mode due to the synergistic effect of Au and Ag nanoparticles,and significantly enhanced the light absorption range and intensity in the visible light range,providing an effective research method for improving the cell's light absorption efficiency.