Synthesis Of Cdse Quantum Dots And Photoelectric Properties Of CdSe QDS-sensitized Solar Cells

The quantum dot-sensitized solar cell is emerging as a low costphotoelectrochemical cell. In this thesis, we assembled CdSe quantumdots in the nanocrystalline film to form the sensitized solar cells in aclean and relatively moderate ways, and subsequently adopted a series ofoptimization measures. The major research work includes the followingthree aspects:CdSe quantum dots were prepared by the chemical bath depositionmethod using inorganic cadmium salt and the precursor of selenium asraw materials. CdSe quantum dots with a cubic zinc blende structureformed at room temperature directly assembled to the nanocrystallinefilm. We could change the amount of sensitized CdSe QDs on thenanocrystalline film by controlling the deposition time. We took a seriesof characterization such as SEM、 XRD、 UV-visble absorption、photocurrent-voltage curve to find the optimal deposition time for5.5hafter fabricating solar cells.The working electrode was modified by titanium tetrachloride solution. Surface treatment can greatly improves the photocurrent andconversion efficiency of the solar cells. Meanwhile, We studied themechanism of the surface modification on the solar cells. The highestconversion efficiency was2.13%, and it was obtained for the quantumdot-sensitized soloar cell after optimizing the modification process timeof90min.We prepared a new type PbS counter electrode, which the formationprocess was studied by SEM、XRD. This article focuses on the impactmechanism of PbS counter electrode and Pt counter electrode for CdSequantum dots sensitized the different films cells. With the combination ofpolysulfide electrolyte, PbS counter electrode significantly improved theconversion efficiency of quantum dot-sensitized solar cells, compared tothe traditional Pt electrode. The preparation and application of PbScounter electrode played an important role in the development ofquantum dot-sensitized solar cells.