Performance Investigation Of ZnO/TiO₂ Photoanode On Quantum Dot Sensitized Solar Cells

The global energy crisis and environmental pollution have gradually become the primary problems threatening human development,to this end,countries have introduced various policies to support the development and utilization of renewable resources.Among them,solar cell has received the most attention and support,has become one of the most likely renewable resources to replace fossil energy.This study takes quantum dot sensitized solar cells?QDSSCs?as the research object,ZnO and TiO₂were prepared as photoanode electron transport layer,depositing CdS/CdSe quantum dots as sensitization,preparation CuS as counter electrode,S^2-/Sn^2-as electrolyte.First,properties of ZnO photoanode quantum dot sensitized solar cells were studied.Then,the rigid and flexible photoanode were prepared with TiO₂ as the substrate,and the related properties were studied.The specific contents are as follows:?1?ZnO nano hollow sphere material was prepared by two step of hydrothermal method,ZnO nano hollow sphere?NS?and ZnO nanoparticles?NP?were prepared into paste by sol-gel method and then sintered on FTO glass as the electron transport layer of the photoanode in quantum dot sensitized solar cell,deposition CdS/CdSe quantum dots and ZnS passivation layer on ZnO film to make ZnO/CdS/CdSe/ZnS photoanode,assembled QDSSCs devices with polysulfide electrolyte and CuS counter electrode to tested the photoelectricity performance.ZnO nano hollow sphere photoanode make the power conversion efficiency?PCE?increased to 1.6%,higher than ZnO NP photoanode?0.84%?,the short-circuit current density increased from 7.27mA/cm² to 10.06mA/cm2,ZnO nano hollow sphere structure can increased the deposition amount of quantum dots,so as to improved the PCE of quantum dots sensitized solar cells.Improved the experimental scheme to prepared the ZnO spherical shell?SS?by one-step hydrothermal method,subsequently,ZnO SS/CdS/CdSe/ZnS photoanode was prepared to assemble the QDSSCs and tested the photoelectric performance of photoanode and solar cells.The influence of electron transport layer structure on quantum dot deposition and QDSSCs performance was investigated by adjusting the thickness of ZnO SS film.When ZnO SS film was 10?m,PCE of QDSSCs can increased to 2.94%.?2?TiO₂ nanoparticle?NP?films were prepared on FTO glass by sol-gel method as electron transport layer,then deposition quantum dots on TiO₂ film to prepared TiO2/CdS/CdSe/ZnS rigid photoanode,by controlling the winding number of SILAR deposition to controlled the deposition amount of CdS quantum dots in the key sensitized layer,and the influence of Cd S quantum dot deposition amount on the photoelectric performance of photoanode and QDSSCs was investigated.After 6 cycles of CdS quantum dot deposition,the PCE reached the threshold value of 2.71%.TiO2conductive gel was prepared by mixing PVA?LiCl and TiO₂ NP,and TiO₂ conductive gel film was prepared on ITO-PET by mechanical pressure method as the electron transport layer of flexible photoanode.The influence of the flexible electron transport layer on the performance of QDSSCs was investigated by controlling the number of CdS quantum dot deposition cycles and the formation of TiO₂ rigid photoanode as the reference group.The conductive gel can significantly improve the flexibility of the film,photoanode remains intact even when bent at a large Angle,however,due to the poor conductivity of the conductive gel,the power conversion efficiency of QDSSCs in the flexible photoanode will be reduced to 0.37%.