| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 101 === In this study, various types of quantum dots were deposited on the surfaces of TiO2 by using the successive ionic layer adsorption and reaction (SILAR) process. We investigated the effect of heterostructure interface on the charge transfer in order to fabricate efficient CuInS2 quantum dot-sensitized solar cells (QDSSC) based on multilayered architecture. Firstly, the photoelectrode was prepared by screen printing of a TiO2 paste on the FTO glass. We pretreated the surfaces of bare TiO2 film with different types of quantum dots as buffer layers to reduce the density of electron trap states. The Jsc of CuInS2-based QDSSC using In2Se3 as the buffer layer benefited from the effective injection of excited electrons at the interfacial region between TiO2 and CuInS2. Then, to further improve the light harvesting efficiency of CuInS2-based QDSSC coating In2Se3 as the buffer layer, we combined CdS or CdSe as the hyper-sensitizers. As a result, the co-sensitization of CuInS2 and CdSe significantly raised the Jsc and FF of the photovoltaic device, yielding a 130% increase in overall efficiency. Finally, the photoelectrode was passivated with the wide band gap semiconductor, ZnS or ZnSe, to prevent the electron leakage from QDs to the polysulfide electrolyte. The QDSSC consisting of In2Se3/CuInS2/CdSe/ZnSe multilayered structure exhibited the best performance with a conversion efficiency of 4.55%.
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