| Quantum dots-sensitized solar cell (QDSSC) is one of the hottest spotlights as the crossdisciplinary research of materials science, physics, and chemistry. Many researchers have forecasted that these devices will be one of the most potential photovoltaics with high-efficiency and low-cost. However, the lower power conversion efficiency which can't compete with that of DSSCs has still been the "bottleneck" for limiting their further development. Based on the recent progress of QDSSC's researches, the exploratory researches were performed on the QDSSC, especially for improving their power conversion efficiency by combining the well-established preparation technologies on the nano-structured fim. The main results and conclusions are summarized as follows:Firstly, a series of CdS quantum dots-sensitized TiO2 nanoparticulate film solar cells were prepared. It was found that the CdS QDs well-covered working electrode can be obtained by increasing the porosity of TiO2 film; the interface contactance of a compact TiO2 layer between FTO substrate and TiO2 working electrode can be improved by sintering the compact layer together with the electrode; after passivated by ZnS layer, the short current density (Jsc) of the CdS QDs sensitized TiO2 solar cells can be improved, with the power conversion efficiency of 1.84%. The solar cell shows good stability after the irradiation of high-voltage mercury lamp for 168 hours, the power conversion efficiency drops as little as for 5%.Secondly, free-standing TiO2 (rutile) nanorod arrays films were successfully prepared by hydrothermal method using the silde glass coated with SnO2 seed layer as the original substrate, through the control of surface texture and exposed crystalline plane of SnO2 and the introduction of screening agent. The obtained free-standing film was transplanted onto FTO glass to fabricate the working electrode for CdS quantum dots-sensitized solar cells. After the passivation with ZnS, the solar cells based on the corresponding working electrode exhibited photo-to-current efficiency of 1.27%.Thirdly, free-standing anatase TiO2 nanorod arrays films were successfully prepared through solvothermal method by using commercial Ti foils as the Ti source and substrate for growth of TiO2 nanorods and using the mixed Br2/CH3OH solution to etch the residual Ti substrate. The obtained free-standing film was transplanted onto FTO glass to fabricate the working electrode for CdS quantum dots-sensitized solar cells. After the passivation with ZnS, the solar cells based on the corresponding working electrode exhibited photo-to-current efficiency of 1.55%.Fourthly, mono-disperse CuInS2 quantum dots with three different types of crystal structure (including chalcopyrite, zinc-blende and wurtzite) were successfully synthesized in oleylamine reaction system via hot-injection method by controlling the reaction rate of the system. It was indicated that the higher reaction rate is propitious to obtain chalcopyrite-structural CuInS2 quantum dots, otherwise, CuInS2 quantum dots with zinc-blende or wurtzite structure will be obtained. The CuInS2 quantum dots can absorb almost the all of visible light.Fifthly, free-standing TiO2 nano-tubes array films with both-end opened are successfully prepared by the two-step anodic oxidations. During the second anodic oxidation, the larger maximum the amplitude of impulsive voltage applied to, the higher percentage of bottom-open tubes area of the free-standing film exhibited. The obtained free-standing TiO2 nano-tubes array films were transplanted onto FTO glass to fabricate the working electrodes, and a novel structure of CuInS2 quantum dots sensitized solar cells were developed tentatively. After the passivation with ZnS, the solar cells based on the corresponding working electrode exhibited photo-to-current efficiency of 0.64%.
|
PDF Full Text Request