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An orange-red-emitting iridium complex (N958) was prepared, and its photophysical and device-based characteristics were investigated. Despite N958 displaying quite poor photophysical properties in solution (acetonitrile), organic light-emitting diode (OLED) devices based on the complex exhibit an efficiency close to 10%.

Reference LPI-ARTICLE-2007-033doi:10.1002/adma.200602172View record in Web of Science Record created on 2007-11-08, modified on 2017-05-12

Ru(4,4-dicarboxylic acid-2,2'-bipyridine) (4,4'-bis(2-(4-(1,4,7,10-tetraoxyundecyl)phenyl)ethenyl)-2,2'-bipyridine) (NCS)(2), a new high molar extinction coefficient ion-coordinating ruthenium sensitizer was synthesized and characterized using H-1 NMR, Fourier transform IR (FTIR), and UV/vis spectroscopies and cyclic voltammetry. Using this sensitizer in combination with a nonvolatile organic-solvent-based electrolyte, we obtain a photovoltaic efficiency of 8.4% under standard global AM 1.5 sunlight. These devices exhibit excellent stability when subjected to continuous thermal stress at 80 degrees C or light soaking at 60 degrees C for 1000 h. An electrochemical impedance spectroscopy study revealed that device stability is maintained by stabilizing the TiO2/dye/electrolyte and Pt/electrolyte interface during the aging process. The influence of Li+ present in the electrolyte on the device photovoltaic parameters was studied, and the FTIR spectral and photovoltage transient study showed that Li+ coordinates to the triethyleneoxide methylether side chains on the K60 sensitizer molecules.

Sun sensitivity: A charge-transfer sensitizer with an ion-complexing moiety formed by oxyethylene side groups (see picture) is used in a solid-state dye-sensitized solar cell. Lithium coordination to the dye backbone produces under realistic conditions photovoltages of nearly 900 mV and efficiencies of 3.8%. (Chemical Equation Presented) © 2005 Wiley-VCH Verlag GmbH and Co. KGaA.

Readily prepared N-functionalized benzotriazole-1-carboximidoyl chlorides are proposed as stable and novel isocyanide dichloride synthetic equivalents. Subsequent condensations of these new intermediates afford polysubstituted guanidines, S-aryl isothioureas, and 2-aminoquinazolin-4-thiones.