Dye-sensitized solar cells based on a single layer deposition of TiO 2 from a new formulation paste and their photovoltaic performance

A new strategy for enhancing the efficiency and reducing the production cost of TiO 2 solar cells by design of a new formulated TiO 2 paste with tailored crystal structure and morphology is reported. The conventional three- or four-fold layer deposition process was eliminated and replaced by a single layer deposition of TiO 2 compound. Different TiO 2 pastes with various crystal structures, morphologies and crystallite sizes were prepared by an aqueous particulate sol-gel process. Based on simultaneous differential thermal (SDT) analysis the minimum annealing temperature to obtain organic-free TiO 2 paste was determined at 400°C, being one of the lowest crystallization temperatures of TiO 2 photoanode electrodes for solar cell application. Photovoltaic measurements showed that TiO 2 solar cell with pure anatase crystal structure had higher power conversion efficiency (PCE) than that made of pure rutile-TiO 2. However, the PCE of solar cells depends on the anatase to rutile weight ratio, reaching a maximum at a specific value due to the synergic effect between anatase and rutile TiO 2 nanoparticles. Moreover, it was found that the PCE of solar cells made of crystalline TiO 2 powders was much higher, increasing in the range 32-84% depending on anatase to rutile weight ratio, than that of prepared by amorphous powders. TiO 2 solar cell with the morphology of mixtures of nanoparticles and microparticles had higher PCE than the solar cell with the same phase composition containing TiO 2 nanoparticles due to the role of TiO 2 microparticles as light scattering particles. The presented strategy would open up new insight into fabrication and structural design of low-cost TiO 2 solar cells with high power conversion efficiency. © 2012 Elsevier Ltd.

New annealing processes and explanation for novel silicon pn junctions formed by proton implantation

Proton-implanted n-type Si wafers were annealed at 950 degrees C to achieve novel pn junctions. The novel pn junctions are explained by the combined use of four models. The background (e.g. oxygen impurity) of an Si wafer is suggested to play a key role in creating the novel pn junction.

New color centers and photostimulated luminescence of BaFCl : Eu2+

Three new absorption bands, appearing around 670, 865 and 980 nm, are observed in BaFCl:Eu2+ phosphors. They are ascribed to F aggregates formed by association of F centers or by trapping of electrons to the primary F-n(+) (n = 2,3,4) centers. The growth curves of F and F-aggregated centers are similar and may be divided into three stages. The photostimulated luminescence (PSL) decays by stimulation into the absorption bands of F centers and of F aggregates are different; the former decay logarithmically and the latter decay hyperbolically. Some non-radiative processes related to F aggregates, such as electron migration, occur accompanying the PSL process, which may reduce the PSL efficiency and sensitivity of the phosphors. (C) 1997 Published by Elsevier Science Ltd. All rights reserved.

A new flow field and its two-dimension model for polymer electrolyte membrane fuel cells (PEMFCs)

A new flow field was designed to search flow fields fitting polymer electrolyte membrane fuel cells (PEMFCs) better due its extensible. There are many independent inlets and outlets in the new flow field. The new flow field we named NINO can extend to be more general when pressures at the inlet and outlet vary and some usual flow fields will be obtained. A new mathematical model whose view angle is obverse is used to describe the flow field.

NEW TOPOLOGICAL INDEX AND PREDICTION OF PHASE-TRANSFER ENERGY FOR PROTONATED AMINES AND TETRAALKYLAMINES IONS

The applications of new topological indices A(x1)-A(x3) suggested in our laboratory for the prediction of Gibbs energy values of phase transfer (water to nitrobenzene) of amine ions are described with satisfactory results. Multiple regression analysis and neural network were employed simultaneously in this study.

SYNTHESIS AND CRYSTAL-STRUCTURES OF A NEW NONCYCLIC LIGAND AND ITS LANTHANIUM(III) COMPLEX

A new non-cyclic ligand, tris(4-carboxy-3-oxabutyl) amine (H3L . HCl) and its lanthanum(III) complex have been prepared and their crystal structures determined. In the lanthanum(III) complex the metal ion is coordinated to one nitrogen atom, three ether o

STUDY ON STRUCTURE-ACTIVITY-RELATIONSHIPS OF ORGANIC-COMPOUNDS - 3 NEW TOPOLOGICAL INDEXES AND THEIR APPLICATIONS

In this paper, three new topological indices, A(x1), A(x2), and A(x3), have been developed for use in multivariate analysis in structure-property relationship (SPR) and structure-activity relationship (SAR) studies. Good results have been obtained by using them to predict the physical and chemical properties and biological activities of some organic compounds.

A new halogenated biindole and a new apo-carotenone from green alga Chaetomorpha basiretorsa Setchell

A new halogenated biindole and a new apo-carotenone have been isolated from the ethanolic extract of the green alga Chaetomorpha basiretorsa Sethcell. On the basis of chemical and spectroscopic methods including 2D NMR technique, their structures have been elucidated as 4,4'-dichloro-5,5'-dibromo-7,7'-dimethoxy-2,2'-bi-1H-indole and 1'S*,4R*-8-(4'-hydroxy-2',6',6'-trimethylcyclohex-2-enyl)-6-methyloct-3E,5E,7E-trien-2-one, respectively.

A new brominated phenylpropylaldehyde and its dimethyl acetal from red alga Rhodomela confervoides

A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde, 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl) propylaldehyde dimethyl acetal and 3-bromo-4,5-dihydroxybenzoic acid methyl ester by spectroscopic techniques including IR, HRFABMS, ID and 2DNMR experiments.

New taxa, names, and combinations in Saxifraga (Saxifragaceae) for the Flora of China

The following new species, new variety, new name, and four new combinations are published for the forthcoming account of Saxifraga L. in the Flora of China, Volume 8: S. epiphylla Gornall & H. Ohba, sp. nov., S. gemmigera Engler var. gemmuligera (Engler) J. T. Pan & Gornall, comb. nov., S. heterotricha Marquand & Airy-Shaw var. anadena (H. Smith) J. T. Pan & Gornall, comb. et stat, nov., S. hypericoides Franchet var. aurantiascens (Engler & Irmscher) J. T. Pan & Gornall, comb. nov., S. hypericoides var. rockii (Mattfeld) J. T. Pan & Gornall, comb. et stat. nov., S. sinomontana J. T. Pan & Gornall, nom. nov., and S. sinomontana var. amabilis H. Smith ex J. T. Pan, var. nov. In addition, the names S. mengtzeana Engler & Irmscher and S. mengtzeana var. cordatifolia Engler & Irmscher are lectotypified here.

Writing the War on Terrorism: Language, Politics and Counter-terrorism

Jackson, Richard, Writing the War on Terrorism: Language, Politics and Counter-terrorism (Manchester: Manchester University Press, 2005), pp.viii + 232 RAE2008