Electron transport and recombination in dye-sensitized solar cells made from single-crystal rutile TiO2 nanowires.
ABSTRACT Contrary to expectations, the electron transport rate in dye-sensitized solar cells made from single-crystal rutile titanium dioxide nanowires is found to be similar to that measured in dye-sensitized solar cells made from titanium dioxide nanoparticles.
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ABSTRACT: Nanoporous TiO2 films are commonly used as working electrodes in dye-sensitized solar cells (DSSCs). So far, there have been attempts to synthesize films with various TiO2 nanostructures to increase the power-conversion efficiency. In this work, vertically aligned rutile TiO2 nanorods were grown on fluorinated tin oxide (FTO) glass by hydrothermal synthesis, followed by deposition of an anatase TiO2 film. This new method of anatase TiO2 growth avoided the use of a seed layer that is usually required in hydrothermal synthesis of TiO2 electrodes. The dense anatase TiO2 layer was designed to behave as the electron-generating layer, while the less dense rutile nanorods acted as electron-transfer pathwaysto the FTO glass. In order to facilitate the electron transfer, the rutile phase nanorods were treated with a TiCl4 solution so that the nanorods were coated with the anatase TiO2 film after heat treatment. Compared to the electrode consisting of only rutile TiO2, the power-conversion efficiency of the rutile-anatase hybrid TiO2 electrode was found to be much higher. The total thickness of the rutile-anatase hybrid TiO2 structures were around 4.5-5.0 μm, and the highest power efficiency of the cell assembled with the structured TiO2 electrode was around 3.94%.Clean Technology. 07/2014; 20(3):306-313.
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ABSTRACT: Single-crystal TiO2 nanorod film was synthesized directly on FTO substrates with various lengths by changing the hydrothermal growth parameters including growth time and growth temperature. The obtained nanorod arrays were incorporated in organic solar cells as buffer layer instead of PEDOT: PSS. Results showed that devices assembled with TiO2 nanorods film of 200 nm in length exhibited a lower open-circuit voltage but a significantly higher short-circuit current density compared to those of normal FTO/PEDOT: PSS/P3HT: PCBM/Al structure with a comparable active layer thickness. Overall the power conversion efficiency was boosted by two-fold. Electrochemical impedance spectroscopy analyses revealed that the improvement in the photovoltaic performance was induced by the inhibited recombination and consequently enhanced electron lifetimeKey Engineering Materials 06/2012; 512:1598-1603.
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ABSTRACT: In this paper, 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) has been used in interface modification of dye-sensitized solar cells (DSCs) with combined effects of retarding charge recombination and Förster resonant energy transfer (FRET). DCJTB interface modification significantly improved photovoltaic performance of DSCs. I-V curves shows the conversion efficiency increases from 4.27% to 5.64% with DCJTB coating. The application of DCJTB with combined effects is beneficial to explore more novel multi-functional interface modification materials to improve the performance of DSCs.Scientific Reports 07/2014; 4:5570. · 5.08 Impact Factor