Two novel branchlike organic dyes (D1 and D2) comprising two di(p-toyl)phenylamine moieties as the electron donor, cyanoacetic acid moieties as the electron acceptor, thiophene or 3-hexylthiophene moieties as the Π-spacer, were designed and synthesized for dye-sensitized solar cells (DSSCs). It was found that the introduction of two di(p-tolyl)phenylamine groups to form the branchlike configuration exhibited better photovoltaic performance due to the improvement of the electron donating and the light-harvesting properties. By the introduction of two di(p-tolyl)phenylamine groups into the framework of D2, it is interesting to note that the UV-vis absorption of D2 showed an obvious blue-shift but also improved molar extinction coefficient compared with that of D3. The transient absorption measurements showed that the dyes D1 and D2 with two di(p-tolyl)phenylamine-substitutes could effectively retard charge recombination between electrons at the TiO 2 and the oxidized dyes. Among the three dyes studied, a maximum power conversion efficiency of 6.41% was obtained under simulated AM 1.5 G solar irradiation (100 mW/cm 2 ) with a DSSC based on D2 dye (J sc ) 11.62 mA/cm 2 , V oc ) 0.73 V, FF ) 0.756) upon the addition of 1.0 × 10 -3 M chenodeoxycholic acid (CDCA) as coadsorbent.

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Electrospinning has the unique ability to produce ultrathin fibers from a rich variety of materials that include polymers, inorganic or organic compounds and blends. With the enormous increase of research interest in electrospun nanofibers, there is a strong need for a comprehensive review of electrospinning in a systematic fashion. This article presents some fascinating phenomena associated with the remarkable features of nanofibers in electrospinning processes and new progress in applications of electrospun nanofibers. Copyright © 2007 Society of Chemical Industry