The dye-sensitized solar cell (DSC) [1,2] is an attractive candidate for a new renewable energy source because of the low-cost materials and the facile manufacturing used in its production. [3] This cell has been intensively studied in the last decade. The photovoltaic effect in a DSC originates at the interface between a redox electrolyte containing iodide and triiodide (I -/I 3 -) ions and a dye-derivatized mesoscopic TiO 2 electrode. For outdoor applications, ionic liquids containing I -and I 3 -ions are the medium of choice because of their high thermal stability, non-flammability, negligible vapor pressure, and low toxicity. [4] Since the diffusion of I -and I 3 -ions in ionic liquids is slow owing to their high viscosity, [5] a thin nanocrystalline TiO 2 film is required to reach a high conversion efficiency. In order to compensate for the lower optical depth of such thin, porous electrodes, a high-extinction-coefficient dye should be used. A similar strategy is applied to other types of viscous electrolytes [6] and organic hole conductors. [7] The present study reports, for the first time, on a DSC combining a high-extinction-coefficient organic sensitizer with an ionic-liquid electrolyte. An indoline dye was employed (referred to as D149 below, Fig. 1), [8] which has an extinction coefficient (68 700 mol -1 cm -1 at 526 nm) that is five times higher than that of the conventional high-efficiency Ru dye (N719, 13 900 mol -1 cm -1 at 541 nm) [9] and reaches 8 % conversion efficiency with a volatile organic electrolyte. A screen-printed double layer, consisting of a nanocrystalline TiO 2 film and a scattering layer, constitute the mesoporous working electrode that supports the organic sensitizer (Fig. 1b). Below, we scrutinize the effect of the film thickness of nanocrystalline TiO 2 films on the photovoltaic performance of ionic-liquid-and acetonitrile (AcCN)-based electrolytes.Results obtained under 100 % sun irradiation are shown in Figure 2. The open-circuit photovoltage (V OC , Fig. 2a) decreases for both the AcCN-and ionic-liquid-based electrolytes with increasing film thickness, due to augmentation of the surface area, which provides additional charge-recombination sites [10][11][12] and enhances the dark current. [13] Moreover, for thick films the outer TiO 2 particle layers do not contribute significantly to the photogeneration of conduction-band electrons, owing to the filtering of light by the dyed particles located close to the fluorinated tin oxide (FTO) glass. The sharing of photoinjected conduction-band electrons by these particles lowers their quasi-Fermi level and hence the V OC . In contrast to the V oc , the short-circuit photocurrent density (J SC ), fill factor (FF), and overall solar-energy-conversion efficiency (g) obtained with the two electrolytes are affected in a different way by the film thickness. For the AcCN solvent (Fig. 2b), J SC increases continuously with film thickness, reaching a plateau value of close to 20 mA cm -2 at 14 lm, while g reaches a maximum of 9 % at a thicknes...

An indoline dye (D205), the synthesis method of which is disclosed in this report, gave high-efficiency organic dye-sensitized solar cells (9.52%) using an anti-aggregation reagent (chenodeoxycholic acid).

TiO(2) nanotube arrays prepared by electrochemical anodization of Ti foils show impressive light to electricity conversion efficiency in the dye-sensitized solar cells (DSCs). The length of the TiO(2) nanotube arrays (5-14 microm) was controlled by varying the anodization time from 2 to 20 h. The influence of nanotube lengths on the photovoltaic performance of DSCs was investigated by impedance. A flexible DSC using TiO(2) nanotube arrays on a Ti foil as a working electrode and polyethylene naphthalate (ITO/PEN) as counterelectrode in combination with solvent-free ionic liquid electrolyte achieved 3.6% photovoltaic conversion efficiency under simulated AM 1.5 sunlight.

We have discovered rotationally split core g-mode triplets and surface p-mode triplets and quintuplets in a terminal age main sequence A star, KIC 11145123, that shows both δ Sct pmode pulsations and γ Dor g-mode pulsations. This gives the first robust determination of the rotation of the deep core and surface of a main sequence star, essentially model-independently. We find its rotation to be nearly uniform with a period near 100 d, but we show with high confidence that the surface rotates slightly faster than the core. A strong angular momentum transfer mechanism must be operating to produce the nearly rigid rotation, and a mechanism other than viscosity must be operating to produce a more rapidly rotating surface than core. Our asteroseismic result, along with previous asteroseismic constraints on internal rotation in some B stars, and measurements of internal rotation in some subgiant, giant and white dwarf stars, has made angular momentum transport in stars throughout their lifetimes an observational science.

We have found a rotationally split series of core g-mode triplets and surface p-mode multiplets in a main sequence F star, KIC 9244992. Comparison with models shows that the star has a mass of about 1.45 M ⊙ , and is at an advanced stage of main sequence evolution in which the central hydrogen abundance mass fraction is reduced to about 0.1. This is the second case, following KIC 11145123, of an asteroseismic determination of the rotation of the deep core and surface of an A-F main-sequence star. We have found, essentially model-independently, that the rotation near the surface, obtained from p-mode splittings, is 66 d, slightly slower than the rotation of 64 d in the core, measured by g-mode splittings. KIC 9244992 is similar to KIC 11145123 in that both are near the end of main-sequence stage with very slow and nearly uniform rotation. This indicates the angular momentum transport in the interior of an A-F star during the main sequence stage is much stronger than that expected from standard theoretical formulations.