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Search Publications by: Dean DeLongchamp (Fed)

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Displaying 151 - 175 of 231

Substrate-dependent interface composition and charge transport in films for organic photovoltaics

June 9, 2009
Author(s)
David Germack, Calvin Chan, Behrang Hamadani, Lee J. Richter, Daniel A. Fischer, David J. Gundlach, Dean DeLongchamp
The buried interface composition of polymer-fullerene blends is found by near edge X ray absorption fine structure (NEXAFS) spectroscopy to depend on the surface energy of the substrate upon which they are cast. The interface composition determines the

Controlling the Formation and Orientation of Terraced Nanoscale Ribbons of a Thiophene-Based Copolymer

March 24, 2009
Author(s)
Dean M. DeLongchamp, Regis J. Kline, Youngsuk Jung, David Germack, Eric K. Lin, Andrew Moad, Lee J. Richter, Michael F. Toney, Martin Heeney, Iain McCulloch
Terraced nanoscale ribbon domains of a poly(2,5-bis(3-alkylthiophen-2-yl) thieno[3,2-b]thiophene) form after thin films are cooled from its highest-temperature phase. A simple flow coating procedure can induce high levels of ribbon orientation and even

Semiconducting Thienothiophene Copolymers: Design, Synthesis, Morphology and Performance in Thin Film Organic Transistors

March 1, 2009
Author(s)
Iain McCulloch, Martin Heeney, Michael L. Chabinyc, Dean DeLongchamp, Regis J. Kline, Michael Colle, Warren Duffy, Daniel A. Fischer, David J. Gundlach, Behrang Hamadani, Rick Hamilton, Lee J. Richter, Alberto Salleo, Martin Shkunov, David Sparrowe, Steve Tierney, Weimin Zhang
Organic semiconductors are emerging as a viable alternative to amorphous silicon in a range of thin film transistor devices. , With the possibility to formulate these p-type materials as inks and subsequently print into patterned devices, organic based

The molecular basis of mesophase ordering in a thiophene-based copolymer

February 18, 2009
Author(s)
Dean M. DeLongchamp, Regis J. Kline, Youngsuk Jung, Eric K. Lin, Daniel A. Fischer, David J. Gundlach, Andrew Moad, Lee J. Richter, Michael F. Toney, Martin Heeney, Iain McCulloch
The carrier mobility of poly(2,5-bis(3-alkylthiophen-2-yl) thieno[3,2-b]thiophene) semiconductors can be substantially enhanced after heating through a thermotropic mesophase transition, which causes a significant improvement in thin film structural order

The Impact of the Dielectric / Semiconductor Interface on Microstructure and Charge Carrier Transport in High-Performance Polythiophene Transistors

May 14, 2008
Author(s)
Youngsuk Jung, Regis J. Kline, Eric K. Lin, Daniel A. Fischer, Michael F. Toney, Martin Heeney, Iain McCulloch, Dean DeLongchamp
The performance of organic field-effect transistors (OFETs) significantly depends on the properties of the interface between the semiconductor and gate dielectric. Here, we study the impact of chemically modified and morphologically controlled dielectrics

Microstructure of oligofluorene asymmetric derivatives in organic thin film transistors

April 22, 2008
Author(s)
Quan Yuan, Stefan C. Mannsfeld, Ming L. Tang, Mark Roberts, Michael F. Toney, Dean DeLongchamp, Zhenan Bao
In organic thin film transistors (OTFT), modifying the molecular chemical structure affects the molecular packing and thin film morphology, which both sensitively influence the charge carrier mobility. A detailed understanding of the interplay of molecular

The Effect of Interfacial Roughness on the Thin Film Morphology and Charge Transport of High-Performance Polythiophenes

March 11, 2008
Author(s)
Y S. Jung, Regis J. Kline, Daniel A. Fischer, Eric K. Lin, Martin Heeney, Iain McCulloch, Dean DeLongchamp
We control and vary the roughness of a dielectric upon which a high-performance polymer semiconductor, poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene) (pBTTT) is cast, to determine the effects of roughness on thin-film microstructure and the