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We demonstrate a method for incorporating plasmon metallic nanoparticles in hierarchical rutile TiO 2 clusters (RTC) assembled from single-crystal nanospindles. The RTC could efficiently improve the diffusion of the photoelectrons, which can be ascribed to the improvement of the connectivity by bridging the neighbouring microflowers through the single-crystal nanospindles. But not all the nanospindles are tightly interconnected, hence organic colloid has been prepared for post-treatment of the device based on RTC by the generation of TiO 2 nanoparticles. When added into Au nanoparticles, localized electric fields can be produced, because Au can excite dye molecules more intensively than incident far-field light. The surface plasmon synergistic effect had been investigated by Uv-vis absorption spectrum of Au@ organic colloid and the relative change of the IPCE. As a result, the cell based on RTC exhibits an overall conversion efficiency of 7.68%, indicating a 17% promotion compared with that derived from commercial P25 (6.58%) which could be ascribed to faster electron transfer of single-crystal nanospindles. With the Au nanoparticles incorporation in RTC, the device achieves a conversion efficiency of 9.15%, resulting in a 11% increase compared to the RTC device post-treated by organic colloid without Au nanoparticles (8.24%), which is attributed to the surface plasmon synergistic of Au nanoparticles. [ABSTRACT FROM AUTHOR]

Liquid electrolytes employing fluorescent perylene are prepared and applied in dye sensitized solar cells (DSSCs). Due to the excellent down-shifting property of perylene, photons with short wavelength (from about 350 to 440 nm) can be absorbed and then converted to ones with longer wavelength (from 450 nm to 550 nm) which can be more efficiently utilized by DSSCs. As a result, device with optimal concentration of 0.05 M perylene presents an efficient improvement in the short-circuit current density ( J sc ), leading to an increase of 11.6% in the power conversion efficiency (PCE) compared with the reference DSSC based on control electrolyte. [ABSTRACT FROM AUTHOR]

A series of dye-sensitized solar cells (DSSCs) with differing amounts of Au nanorods (AuNRs) (coated with a SiO 2 layer as a core–shell AuNR@SiO 2 (AuNRS)) composited photoanodes are prepared. The influences of different amounts of AuNRSs on the performance of the composite photoanodes and DSSCs are investigated. Studies revealed that, by increasing the amount of AuNRSs, the intensity of the light absorption spectra of the photoanodes is gradually increased while the dye absorbed is reduced. The short-circuit current density ( J sc ), open-circuit voltage ( V oc ) and photoelectric conversion efficiency ( η ) increased gradually first and then decreased with the increase of AuNRSs, while the charge transfer resistance R 2 and the dark current showed an opposite change trend. The optimal properties were obtained in the 2.0 wt% AuNRSs doped DSSC, with a maximum J sc of 15.88 mA cm −2 , a highest V oc of 730 mV and a best η of 7.21%, giving 20.8%, 38 mV and 23.0% higher than those of the conventional pure TiO 2 -based DSSC, respectively. The significant improvements in the properties of the optimal DSSC are attributed to the increase of the light coupling and thus the light absorption of the dye due to the localized surface plasmon resonance of the AuNRSs. [ABSTRACT FROM AUTHOR]

Abstract: Thin titanium dioxide (TiO2) semiconductor layer with different scattering layers are investigated in dye-sensitized solar cells (DSSCs). Usually, the scattering layer is placed after the photoanode films in order to harvest more incidents light. The scattering layer based on rutile phase TiO2 is prepared, and placed in the different position of the photoanode films (on the surface of the FTO glass, between the two layers of transparent TiO2 film and after the transparent TiO2 film). We use STT, TST and TTS as marks (T and S represent the transparent TiO2 layer and the scattering layer respectively). The result of this study indicates that STT which has the lowest incident light harvesting efficiency demonstrates the highest electron collection efficiency, while TTS which has the highest incident light harvesting efficiency sacrifices the electron collection efficiency greatly. It is discovered that TST, of which the incident light harvesting efficiency basically remains unchanged compared to TTS, reveals higher electron collection efficiency and achieves the maximum photovoltaic conversion efficiency (7.0%). By applying UV-Visible and diffuse reflectance spectroscopy, electrochemical impedance spectroscopy (EIS), the effects of the incident light harvesting and electron collection efficiencies on different cells are analyzed. It makes the best use of this scattering layer and has a reference for the application of other scattering layer types. [Copyright &y& Elsevier]

Abstract: TiO2 doping has been widely used to improve the performance of dye-sensitized solar cells. In this paper, we study the use of N as a dopant of TiO2 in dye-sensitized solar cells (DSSCs), analyzing the effect on the photovoltaic properties of the cells based on different amounts of N doping. Results indicate that the dye absorption is increased, which would enhance the amount of photoelectron; moreover, the resistance (R 3) of the electron transport within photoelectrode and electron lifetime of it are improved by N doping. The above two reasons would lead the high short circuit current density (J sc). However, owing to the sites of recombination and severe defects introduced, the trend of dye absorption, R 3 and electron lifetime is opposite when the amount of N doping is more than 3%. Finally, we find that the optimal amount of N doing is 3%, which outstandingly increase the performance of DSSCs. The conversion efficiency of the DSSCs can be reached to 6.25% when using the 3% N-doped TiO2 photoelectrode, and this efficiency is 23.03% higher than that of the pure TiO2. [Copyright &y& Elsevier]