Preparation And Photoelectric Performance Of Electrode For Quantum Sensitized Solar Cells

Quantum dot sensitized solar cells?QDSCs?have the potential to be used widely because them have the advantage of being environmentally friendly,low cost,and high theoretical energy conversion rate.In this paper,aiming at the problem that the photoelectric conversion efficiency is low of the QDSCs,the photoanodes and the counter electrode of the QDSCs have been improved.The main work of this paper is as follows:The TiO₂/CdS/CdSe/ZnS co-sensitized composite photoanodes were assembled by successive ionic layer absorption and reaction?SILAR?method and chemical bath deposition?CBD?method.By optimizing the adsorption of CdS and CdSe quantum dots,the best TiO₂/CdS/CdSe quantum dot co-sensitized composite photoanodes were obtained.And the effect of ZnS passivation layer on the photoelectric properties of the battery was studied.The result indicates that an appropriate amount of quantum dot adsorption can improve the photoelectric conversion efficiency of the battery.The proper amount of ZnS passivation layer can effectively hinder the recombination between photogenerated electrons and oxidized electrolyte,and improve the utilization rate of photogenerated electrons.Mn²⁺dopedTiO₂/Mn-CdSphotoanodesandTiO₂/Mn-CdS/Mn-CdSe co-sensitized composite photoanodes were prepared by SILAR method and CBD method.In this paper,the photoelectric properties of different manganese salts doped TiO₂/Mn-CdS were investigated.And the optimum doping concentration of Mn²⁺dopedphotoanodeswereoptimized.Theelectrochemicalpropertiesof TiO₂/CdS/CdSe co-sensitized composite photoanodes by different doping methods were compared and analyzed.The results show that the appropriate Mn²⁺doping can improve the photoelectric properties of the battery,and TiO₂/Mn-CdS/Mn-CdSe/ZnS co-sensitized composite photoanodes are superior to other photoanodes.The photoelectric conversion efficiency is 3.15%,it is 70%higher than that of TiO₂/CdS/CdSe/ZnS co-sensitized composite photoanodes which is not doped with Mn²⁺.CoS and CuS were potentiostatic deposited sequentially on the surface of FTO conductive glass substrate to fabricate the FTO/CoS/CuS composite counter electrode for quantum dot sensitized solar cells.FTO/CoS/CuS composite counter electrode was prepared at a suitable voltage and electrodeposition time,and the effects of electrolytic temperature on the morphology and electrocatalytic activity of prepared counter electrode were studied.The result indicates that FTO/CoS/CuS composite counter electrode provides higher reflectivity and superior electrocatalytic activity.Compared with that of Au,FTO/CoS and FTO/CuS counter electrode,the photovoltaic conversion efficiency of FTO/CoS/CuS composite counter electrode is increased by 118.3%,48.8%and 26.8%,respectively.