Interplay of nanoscale domain purity and size on charge transport and recombination dynamics in polymer solar cells.

Charge transport and bimolecular recombination dynamics were correlated with nanomorphology in polymer solar cells. The morphology of poly(diketopyrrolopyrrole-terthiophene) (PDPP3T) and phenyl-C61-butyric acid methyl ester (PC60BM) blend films was modified using different solvent additives namely 1-chloronaphthalene (CN), 1,8-diiodooctane (DIO) and 1,8-octanedithiol (ODT) and their role on steady state and transient optoelectronic properties was investigated. The energy filtered transmission electron microscopy (EFTEM) images showed that additives (e.

Kelvin probe force microscopic imaging of the energy barrier and energetically favorable offset of interfaces in double-junction organic solar cells.

A double-junction polymer solar cell (PSC) has attracted extensive attention as a promising approach to increasing efficiency. Tunneling/recombination interlayers between subcells play a critical role in double-junction PSCs. Interlayers include electron-transport layers (ETLs) such as Nb₂O₅, ZnO, and TiO(x) and hole-transport layers (HTLs) including PEDOT:PSS.

Theoretical study of two-photon absorption properties and up-conversion efficiency of new symmetric organic π-conjugated molecules for photovoltaic devices.

Organic material with high intensity of two-photon absorption (TPA) induced fluorescence can be used as the frequency up-converter materials for improving efficiency of the solar cells. In this work, the organic molecular structures were designed by symmetrically grafting two elongated conjugated linkers on a conjugated core and then adding donor groups at both terminals. Fluorene derivatives as a core acceptor, phenylethynyl as the conjugated linker and diphenylamino or methyl-9H-carbozole as the donor end groups were selected.

TiO2 nanotube membranes on transparent conducting glass for high efficiency dye-sensitized solar cells.

Crack-free TiO(2) nanotube (NT) membranes were obtained by short time re-anodization of a sintered TiO(2) NT array on Ti foil, followed by dilute HF etching at room temperature. The resulting freestanding TiO(2) membranes were opaque with a slight yellow color having one end open and another end closed. The membranes were then fixed on transparent fluorine-tin-oxide glass using a thin layer of screen-printed TiO(2) nanoparticles (NPs) as a binding medium.

Electrospun carbon nanofibers as low-cost counter electrode for dye-sensitized solar cells.

Electrospun carbon nanofibers (ECNs) have been explored as an electrocatalyst and low-cost alternative to platinum (Pt) for triiodide reduction in dye-sensitized solar cells (DSCs). The results of electrochemical impedance spectroscopy (EIS) and cyclic voltammetry measurements indicated that the ECN counter electrodes exhibited low charge-transfer resistance (Rct), large capacitance (C), and fast reaction rates for triiodide reduction. Although the efficiency (η) of ECN-based cells was slightly lower than that of Pt-based cells, their short circuit current density (Jsc) and open circuit voltage (Voc) were comparable.

Excitation-dependent fluorescence of triphenylamine-substituted tridentate pyridyl ruthenium complexes.

Two polypyridyl ruthenium complexes, bis[4-(N,N'-diphenylamino)phenyl-2,2':6',2''-terpyridine]ruthenium(II) (1) and bis[4'-(4-{2-[4-(N,N'-diphenylamino)phenyl]ethylene}phenyl)-2, 2':6',2''-terpyridine]ruthenium(II) (2), have been synthesized. They possess an extended conjugation and strongly coupled electronic states. The features of these compounds were carefully studied from several respects.

Geometry dependence of field enhancement in 2D metallic photonic crystals.

Geometry dependence of surface plasmon resonance of 2D metallic photonic crystals (PCs) was assessed using rigorous 3D finite difference time domain analysis. PCs of noble metallic rectangular and cylindrical nanopillars in square and triangular lattices on thick noble metal film were simulated for maximum field enhancement. It was found that the period, size and thickness of the nanopillars can be tuned to excite of surface plasmons at desired wavelengths in visible and near-infrared ranges.

Monoporphyrinate ytterbium(iii) complexes with new ancillary ligands: synthesis, structural analysis and photophysical investigation.

A method for the preparation of neutral monoporphyrinate ytterbium(iii) complexes [Yb(TPP)(L)(H(2)O)] from their precursor [Yb(TPP)(H(2)O)(3)]Cl is presented, where TPP is 5,10,15,20-tetraphenylporphyrinate dianion and L are the bidentate anions of 8-hydroxylquinoline (HOQ), 1-hydroxyl-7-azabenzotriazole (HBTA), 2-benzimidazolylguanidine (HGBI) and 1,1,1,5,5,5-hexafluoro-2, 4-pentanedione (HHFA). The new complexes were characterized by elemental analysis and mass spectroscopy. The structure of [Yb(TPP)(OQ)(H(2)O)] was ascertained by single-crystal X-ray diffraction revealing the central ytterbium(iii) ion to be seven coordinate.