At present, the photovoltaic performance of quantum dot-sensitized solar cells (QDSCs) is still much lower than conventional DSCs. Appropriate porous TiO(2) photoanodes for QDSCs need to be further investigated, and optimization of the nanoparticle-based photoanodes is highly desirable as well. In this article, the influence of the structural properties of various TiO(2) photoanodes on CdS/CdSe-sensitized solar cells have been systematically studied. Quantitative analyses of light-harvesting efficiency (LHE) and electron-transfer yield (Φ(ET)) for the QDSCs are investigated for the first time. It is revealed that the LHE increases in the long wavelength region with the addition of large size TiO(2) particles to the transparent film. In the meantime, the balance between the light scattering and surface area also needs to be controlled, which can significantly restrain the dark current of the device. A double-layer photoanodic structure can give 4.92% of light-to-electricity conversion efficiency with a photoactive area of 0.15 cm(2).

a b s t r a c tIn this paper, the Lie symmetry analysis is performed for the general Burgers' equation. The exact solutions and similarity reductions generated from the symmetry transformations are provided. Furthermore, the all exact explicit solutions and similarity reductions based on the Lie group method are obtained, some new method and techniques are employed simultaneously. Such exact explicit solutions and similarity reductions are important in both applications and the theory of nonlinear science.

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We, for the first time, employed aqueous colloidal CuInS 2 in quantum dot sensitized solar cells. With heat treatment and introduction of CdS buffer layer, a power conversion efficiency of 1.47% was achieved. The CuInS 2 quantum dot made without using organic solvents offers facile fabrication and potential for further photovoltaic application.Chalcopyrite light adsorption material CuInS 2 , with long-term stability and low toxicity, shows excellent photovoltaic performance in thin film solar cells. 1 However, fabrication by magnetron sputtering in vacuum or a hydrazine based solution process are costly or highly toxic, hindering scale-up of production. 2 Efforts to apply CuInS 2 in other low-cost and environment-friendly devices have been launched in recent years. 3,4 Of particular interest is the quantum dot sensitized solar cells (QDSSCs), in which quantum dots (QDs) are focused on CdSe, CdS, CdTe, PbS, PbSe etc. 5,6 However most of them are toxic or air-sensitive. Free of these weaknesses, CuInS 2 QD is a proper light adsorption material for QDSSCs, and moreover, its energy band gap can be tuned by replacing sulfur (S) with selenium (Se). 7 However, up to now, reports on successful CuInS 2 based QDSSCs are quite rare. Teng et al. used CuInS 2 coated with CdS as sensitizers on TiO 2 electrode to fabricate photoelectrochemical cells, and saturated photocurrent density of 7.7 mA cm À2 was obtained at a bias potential higher than 0.2 V. 4 Zn-doped CuInS 2 QDs with ZnS core-shell structure sensitized ZnO nanotube QDSSC devices yielded an efficiency of 0.7%. 8 In their work, CuInS 2 QDs with long fat chains were synthesized in an organic solvent system. To sensitize the oil phobic TiO 2 or ZnO, the organic ligands with long fat chains have to be removed or replaced, which was a rather demanding process with poor reproducibility. Although researchers had tried to employ CuInS 2 synthesized in hydrophilic solvent in solar cells, their photovoltaic performances were seldom reported. 9,10Here we utilized the CuInS 2 QDs synthesized in aqueous solution as the sensitizer for a TiO 2 photoanode, active carbon coated fluorine doped SnO 2 (FTO) conductive glass 11,12 as the counter electrode and polysulfide aqueous solution as the electrolyte to fabricate the QDSSCs. The CuInS 2 QDs synthesized in water without long fat chains of organic ligand is significantly easier and more controllable route to assemble the QDSSCs.The CuInS 2 QD colloid was prepared according to the literature 13 with slight modification. In detail, 145 ml deionized water was aerated by N 2 for 30 min to dispel air. 2 ml Cu(Ac) 2 (0.125 M), 2 mL InCl 3 (0.125 M) aqueous solution were mixed with the deaired water while stirring. 1 mL fresh mercapto acetic acid (MAA) aqueous solution, with MAA and water volume ratio equalling 1 : 5, was added. As the mixture turned clear, 1 mL Na 2 S (0.5 M) was injected quickly to form an orange colloid, which was finally concentrated to 20 ml via rotary evaporation. XRD patterns clearly presented the existence of CuInS ...