Preparation And Photoelectric Properties Of Quantum Dot Sensitized Photoanode

In recent years,with the increasing depletion of fossil fuels,clean energy batteries have received great attention.Numerous solar cells have been used for photoelectric conversion.Among them,quantum dot sensitized solar cells(QDSSCs)have been widely investigated due to a high theoretical photoelectric conversion efficiency and low-cost.However,it still requires further investigation for pratical application and its efficiency is not stable enough,far from its theoretical efficiency value.Therefore,how to improve the photoelectric conversion ability has become the focus of attention.In this thesis,by introducing into two-dimensionalmaterial g-C3N4,we obtained g-C3N4/TiO2 mesoporous structure photoanodeand g-C3N4/TiO2 nanosheets composite structure photoanode.By changingpreparation parameters of photoanodes,we studied the variations in the performance of the solar cell,providing the experimental reference for the further study of quantum dot sensitized solar cell.The main research resultsare shown as follows:1.The QDSSCS were fabricated using mesoporous TiO2 film as photoanode,CdTe quantum dots as the sensitization agent,with CuS nanoparticles as the conuter electrode of the cell device,the effects of different deposition time of CdTe quantum dots on the performance of the cell was studied.The results showed that in 18 h,24h,30 h three deposition conditions,the cell with 24 h deposition showed the best performance.2.We introduced two-dimensional carbon nitride(g-C3N4),to prepare g-C3N4/TiO2 mesoporous photoanode.A spin coating slurry was prepared by mixing different proportions of carbon nitride and P25 nanoparticles,and then the FTO conductive glass coated with the slurry was sintered at 450 degrees for 3h.Using CdS/CdSe/ZnS quantum dots as sensitizer and CuS as counter electrode for the cell assembling.By changing the mixing ratio of carbon nitride,the photoelectric conversion performance was investigated.The results showed that the matched level structure between g-C3N4 and TiO2 enhanced theseparation and transport of photogenerated carriers,and the addition of g-C3N4 significantly improve the solar cell open circuit voltage and short circuit current,making the efficiency increasefrom3.39% to 4.14%.3.Using g-C3N4/(001)-facetedTiO2 nanosheet film as photoanode,CdS/CdSe/ZnS quantum dots as sensitizer,CuS as the counter electrodeof the cell device.By changing the doping amount ofg-C3N4 to obtain experimental data of photoelectric properties of the solar cell.The results showed that the open circuit voltage,short circuit current and fill factor of the solar cell are higher than that of the undoped photoanode.