Application Of Interface Control Of Quantum Dot Sensitized Semiconductor Nanocrystalline Films In Solar Cells

In recent years,quantum dot sensitized solar cells(QDSSCs)have received extensive attention.The photoelectric conversion performance of QDSSCs has also been significantly improved.Surface treatment of the photoanode interface is a common method to improve the photoelectric performance of QDSSCs.In this thesis,CuInS2 quantum dot-sensitized photoanode was post-treated with CdS and ZnS by SILAR method.Improve the photoelectric conversion efficiency of the QDSSCs and investigated the role of two materials in double post-treatment.On this basis,CuInS2 QD and CdSe QDs were used as the light absorbing layer,and Spiro-OMeTAD was used as the hole transport layer(HTL)to initially try the preparation of solid QDSSCs.The specific research results are as follows:1?CuInS2 quantum dots were prepared by hydrothermal synthesis method and sensitized to TiO2 film to obtain TiO2/CuInS2 photoanode.Continuous ion layer adsorption reaction(SILAR)was used to deposit CdS and ZnS on the surface of the photoanode;through the photoelectric conversion performance test and electrochemical impedance spectroscopy,UV-visible absorption and IPCE test research,it was found that the post-treatment of ZnS and CdS affected the battery performance Different from the mechanism of action:ZnS treatment inhibits electron recombination and increases the photovoltage of the battery,but there is no significant improvement in the absorption of the photoanode.The increase in photocurrent comes from the suppression of the increase in electron injection after recombination.The CdS treatment enhances the light absorption of the photoanode.The increase in the photocurrent of the solar cell is mainly due to the increase in electron injection caused by the absorption enhancement.The addition of CdS increases the electron recombination,resulting in a decrease in the photovoltage.2?Combined with the different function characteristics of ZnS and CdS,dual post-treatments of ZnS/CdS and CdS/ZnS were carried out on the photoanode,which further improved the photoelectric conversion efficiency of the solar cell,which reached 5.78%and 5.66%respectively.Electrochemical impedance spectroscopy,ultraviolet-visible absorption,and IPCE tests show that the role of CdS is to enhance the light absorption of the photoanode when CdS is treated after ZnS.When ZnS is treated after CdS,the effect of ZnS also promotes the light absorption of the photoanode.At the same time,we found that the effect of ZnS on QDSSCs photoanode suppression recombination is only effective when it is in direct contact with quantum dots.3?The immersion method is used to deposit the CuInS2 quantum dots synthesized hydrothermally and the CdSe quantum dots synthesized by thermal injection method.All of them ware deposited onto the TiO2 film to prepare a light-absorbing layer,and to form a solid quantum dot solar cell with the silver back electrode of the hole transport layer.The SILAR method was used to process the light-absorbing layer of the solid-state quantum dot solar cell with CdS quantum dots,which improves the photoelectric conversion efficiency of the solid-state solar cell.