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Search Publications by: Daniel A Fischer (Fed)

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Displaying 76 - 100 of 231

Critical Role of Side-Chain Attachment Density on the Order and Device Performance of Polythiophenes

October 30, 2007
Author(s)
Regis J. Kline, Dean DeLongchamp, Daniel A. Fischer, Eric K. Lin, Lee J. Richter, Michael L. Chabinyc, Martin Heeney, Iain McCulloch
High performance, solution processable semiconductors are critical to the realization of low cost, large area electronics. We show that a signature molecular packing motif - side-chain interdigitation - correlates to high performance for a large and

Influence of Indium-Tin Oxide Surface Structure on the Ordering and Coverage of Organosilane, Carboxylic Acid and Thiol Monolayers

May 17, 2007
Author(s)
M Cerruti, C Rhodes, M Losego, A Efremenko, Jon-Paul Maria, Daniel A. Fischer, D L. Feldheim, S Franzen, Jan Genzer
We report on the formation of organosilane-, carboxylic acid- and thiol-based self assembled monolayers (SAMs) on two lots of commercially prepared Indium Tin Oxide (ITO) thin films. Contact angle measurements, electrochemical experiments, and near-edge x

Ferroelectric Distortion in SrTiO3 Thin Films on Si(001) by X-Ray Absorption Fine Structure: Experiment and First-Principles Calculations

April 23, 2007
Author(s)
Joseph C. Woicik, Eric L. Shirley, C S. Hellberg, S Sambasivan, Daniel A. Fischer, B D. Chapman, E A. Stern, P Ryan, D L. Ederer, H Li
Ti K and Ti L2,3 edge x-ray absorption fine-structure near-edge spectra of SrTiO3 thin films grown coherently on Si(001) reveal the presence of a ferroelectric (FE) distortion at room temperature. This unique phase is a direct consequence of the

A Study of the Packing Density and Molecular Orientation of Bimolecular Self-Assembled Monolayers of Aromatic and Aliphatic Organosilanes on Silica

April 12, 2007
Author(s)
M B. Smith, K Efimenko, Daniel A. Fischer, S E. Lappi, P E. Kilpatrick, Jan Genzer
Bimolecular self-assembled monolayers (SAMs) of aromatic and aliphatic chlorosilanes were self-assembled onto silica and their characteristics were established by contact angle measurement, near-edge X-ray adsorption fine structure spectroscopy, and

High Carrier Mobility Polythiophene Thin Films: Structure Determination by Experiment and Theory

March 19, 2007
Author(s)
Dean M. DeLongchamp, Regis J. Kline, Eric K. Lin, Daniel A. Fischer, Lee J. Richter, Leah A. Lucas, Martin Heeney, Iain McCulloch, John E. Northrup
We exploit the unprecedented crystallinity of poly(2,5-bis(3-alkylthiophene-2-yl)thieno[3,2-b]thiophenes) (pBTTTs) high performance semiconducting polymers to study structural detail within 25 nm thick films of a pBTTT with tetradecyl side chains (pBTTT

Enhancement of Engine Oil Wear and Friction Control Performance Through Titanium Additive Chemistry

February 27, 2007
Author(s)
J M. Guevremont, G H. Guinther, D Szemenyei, Mark Devlin, T-C Jao, Cherno Jaye, Joseph Woicik, Daniel A. Fischer
Traditionally, wear protection and friction modification by engine oil are provided by zinc dithiophosphate (ZDDP) or other phosphorus compounds. These additives provide effective wear protection and friction control on engine parts through formation of a

Interrogation of 'Surface', 'Skin' and 'Core' Orientation in Thermotropic Liquid-Crystalline Copolyester Moldings by Near-Edge X-Ray Absorption Fine Structure and Wide-Angle X-Ray Scattering

February 26, 2007
Author(s)
S Rendon, Robert A. Bubeck, L S. Thomas, W R. Burghardt, A Hexemer, Daniel A. Fischer
Injection molding of thermotropic liquid-crystalline polymers (TLCPs) can result in molded articles the exhibit complex orientation states that vary considerably as a function of depth in the part. Skin-core morphologies are often observed in TLCP moldings

Measuring Molecular Order in Poly(3-alkylthiophene) Thin Films with Polarizing Spectroscopies

January 16, 2007
Author(s)
Marc Gurau, Dean DeLongchamp, Brandon M. Vogel, Eric K. Lin, Daniel A. Fischer, S Sambasivan, Lee J. Richter
We measured the molecular order of poly(3-alkylthiophene) chains in thin films before and after melting through the combination of several polarized photon spectroscopies: infrared (IR) absorption, variable angle spectroscopic ellipsometry (SE), and near

Combinatorial screening of the effect of temperature on the microstructure and mobility of a high performance polythiophene semiconductor

January 1, 2007
Author(s)
Leah A. Lucas, Dean M. DeLongchamp, Brandon M. Vogel, Eric K. Lin, Michael J. Fasolka, Daniel A. Fischer, Iain McCulloch, Martin Heeney, Ghassan Jabbour
Using a gradient combinatorial approach, the authors report the effects of temperature on the microstructure and hole mobility of poly2,5-bis3-dodecylthiophen-2ylthieno3,2-bthiophene thin films for application in organic field-effect transistors. The