The Study Of Quantum Dot-sensitized Solar Cells Based On Hydrotalcite-like Compounds Containing Tin Or Titanium

Hydrotalcite-like compounds(HTlc),a category of layered hydroxide materials with special structure and properties,is composed of two or more metallic elements.With excellent physical and chemical properties,HTlc has been widely used in medicine,adsorption,catalysis,energy and many other fields.Quantum dot sensitized solar cells(QDSSC)are quite promising for their easy fabrication and satisfactory power conversion efficiency(PCE).QDSSC can be fabricated by using mixed metal oxides obtained from HTlc precursor as photoanode material,which provides a new research idea for quantum dot sensitized solar cells.In this paper,Zn-Sn HTlc and Zn-Ti HTlc were obtained by urea method and relevant mixed metal oxides were obtained by calcining the HTlc precursor.XRD,SEM,UV-vis were used to study the structure,morphology,absorption of HTlc and relevant mixed metal oxides.The application of mixed metal oxides as photoanode for QDSSC was studied and graphene was added to improve the PCE.(1)Zn-Sn HTlc was prepared by urea method and relevant mixed metal oxides were obtained by calcining the HTlc precursor,and the obtained mixed metal oxides were used as photoanode for QDSSC.Successive ionic layer adsorption and reaction(SILAR)was used to deposit CdS quantum dots.Different amounts of CdS quantum dots can be deposited on the photoanode with various SILAR cycles,and the influence of the SILAR cycles on the performance of QDSSC was studied.The maximum power conversion efficiency was 0.48%when the photoanode were sensitized eight cycles.With the help of energy diagram and electrochemical impedance spectroscopy,the factors that limited the PCE were discussed.(2)Zn-Ti mixed metal oxides obtained from HTlc precursor were used as photoanode,and graphene was added to get Zn-Ti MMO/graphene nanocomposite photoanode.SILAR was used to deposit CdS quantum dots,and the influence of the amounts of graphene on the performance of QDSSC was studied.The PCE reached a peak value of 0.44%at a graphene ratio of 0.2 wt%and increased 37.5%compared with that based on plain Zn-Ti MMO working electrode.(3)By comparing different photoanodes,along with J-V curve,electrochemical impedance spectroscopy,main factors that limited the performance of QDSSC were discussed.