The Performance Optimization Of Dye-Sensitized Solar Cells By Nano-Metal Surface Plasmon Resonance

For easing the problem of energy crisis caused by industry’s rapid development,researchers pay more and more attention to the new energy,especially clean pollution-free renewable energy research.Dye-sensitized solar cells("DSSCs")have attracted the researchers’ interest in the merits of low production costs,simple processes,and relatively high conversion efficiency.In this paper,we mainly focuses on the performance influence of the precious metals nanoparticles and the upconversion phosphors to dye sensitized solar cell and its mechanism,The study has two aspects:Preparation of core-shell structure nanoparticles of Au@SiO2 by Sol-gel method,then a series of composite photoanode films with different amounts of core-shell structure nano-Au@SiO2 are prepared.Studies revealed that,by introduce the Au@SiO2,the intensity of the light absorption spectra of the dye loaded on surface of photoanode,the short-circuit current density(Jsc)and the photoelectric conversion efficiency(η)of the dye-sensitized solar cell are greatly increased.The optimal properties were obtained in the 0.3%Au@SiO2 doped DSSCs with a maximum Jsc of 15.5 mA·cm-2,a best photoelectric conversion efficiency of 6.49%,giving 17.5%higher than the η of the conventional pure TiO2-based DSSCs.The improved performance of the optimal DSSCs are attributed to the localized surface plasmon resonance of the Au to increase the light absorption of the dye load on photoanode and the effectively restraint of SiP2 on the dark-current.Preparation of different grain size of triangular Ag nanometer sheet(referred to as "T-Ag")by Seed mediated growth method and dual core shell structure upconversion phosphors NaYF4@SiO2 @ TiO2(referred to as "NST")by hydrothermal method.The mass ratio to 0.5%of T-Ag,to 15%of NST are dopped in DSSCs photoanode films.Studies revealed that,by introduce the T-Ag or NST,the η of the DSSCs give 14.3%and 10%higher than the η of the conventional pure Ti02-based DSSCs.When the T-Ag and NST are dopped in photoanode films together,the short-circuit current density and the photoelectric conversion efficiency further enhanced,namely 16.27 mA-cm-2 and 6.99%,giving 17.7%and 22%higher than the conventional pure TiO2-based DSSCs.The improved performance of the optimal DSSCs are attributed to as follows:1)The localized surface plasmon resonance of T-Ag greatly increase the light absorption of the dye load on photoanode;2)T-Ag can increase the optical path in the film by scattering of the incident light,which increases the chance to capture the sunlight of dye;3)upconversion phosphors,which can transform nearinfrared photons into visible photons,then can be absorbed by dye;4)Submicron dimension upconversion phosphors can be used as scattering center,effectively increase light capture rate of dye;5)Coated silica shell effectively solves the problem of the electron trapping caused by bare NaYF4:Er3+ and Yb3+ surface defects.