Performance Optimization Of Dye-sensitized Solar Cells By Incorporation Of Au-Nanoparticle Hollow Multishell Microspheres

With the rapid development of the social economy,the demand for energy in human society has also increased rapidly.It is an undeniable fact that the depletion of traditional fossil energy.The development of green clean energy to replace the traditional fossil energy is an important problem to be solved urgently today.Solar energy is one of the important clean renewable energy.Solar cell is an important photovoltaic device for the efficient use of solar energy.The dye sensitized solar cell（DSSC）has become favored by its high photoelectric conversion efficiency,low cost,and easy for large-scale production.As an important part of a DSSC,photoanodes plays a crucial role in enhancing the performance of the DSSC and therefore is of special research importance.In this paper,the localized surface plasmon resonance effect（LSPR）of gold（Au）nanoparticles and the design of the novel hollow multishell microsphere composited photoanodes are used to improve the performance of DSSCs.The main contents are as follows:Novel double shell Au@SiO₂@TiO₂（AST）microspheres are synthesized by liquid phase method to form their composite photoanodes and DSSCs.The composite photoanodes and DSSCs with different concentrations of AST microspheres are studied.The study indicates that the AST microspheres have enhanced the absorption of incident light in the photoanodes,improved the short-circuit current（Jsc）and photoelectric conversion efficiency（PCE）of DSSCs.The best Jsc and PCE of the optimal DSSC doped with microspheres are 15.23 mA cm-2 and 6.7%,greatly enhanced by 20.9%and 19.0%,respectively,than those of the conventional DSSCs with pure TiO₂ photoanodes.The remarkable improvement of the performance of these DSSC is attributed to:1)the Au nanoparticle surface plasmon resonance in AST microspheres significantly enhanced the absorption of light and the short-circuit current of the DSSCs;2)the SiO₂ insulating layer effectively prevented the direct contact of the Au particles from the electrolyte and the dyes to avoid being corroded:3)TiO₂ thin layer is favorable for more dye adsorption.Novel hollow multishell SiO₂@Au@TiO₂（HSAT）microspheres are synthesized by multi-step method to form composite photoanodes and DSSCs.The composite photoanodes and DSSCs with different amount of HSAT microspheres are studied.The study indicates that the HSAT microspheres have enhanced the scattering and absorption of incident light in the photoanodes,reduced the interface transmission resistance,increased the electron lifetime,and thus significantly improved the Jsc and PCE of the DSSCs.The maximal Jsc and PCE of the optimal DSSC doped with HSAT microspheres are 15.83 mA cm-2 and 7.21%,greatly enhanced by 21.0%and 20.4%,respectively,than those of the conventional DSSC with pure TiO₂ photoanodes.These remarkable enhancements in the properties of the DSSCs can be attributed to the dual effects of HSAT microspheres,i.e.,the LSPR of Au nanoparticles inside the shells and the strong light scattering of hollow spheres,their synergistic and complementary effects have significantly improved the absorption and utilization on incident light and thus the PCE of DSSC.Such synergistic and complementary effects of the different functions are also likely expected to play roles in the performance improvements in other similar solar cells.