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Search Publications by: Dean DeLongchamp (Fed)

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Displaying 51 - 75 of 231

A simple and robust approach to reducing contact resistance in organic devices

December 3, 2018
Author(s)
Lamport Zachary, Katrina Barth, Hyunsu Lee, Martin Guthold, Iain McCulloch, John E. Anthony, Lee J. Richter, Eliot Gann, Dean DeLongchamp, Oana Jurchescu
Efficient injection of charge carriers from the contacts into the semiconductor layer is crucial for achieving high-performance organic devices. The potential drop necessary to accomplish this process yields a resistance associated with the contacts

Advancing the computational methodology of rigid rod and semiflexible polymer systems: A new solution to the wormlike chain model with rod-coil copolymer calculations

October 3, 2018
Author(s)
Adam F. Hannon, Regis J. Kline, Dean DeLongchamp
A wormlike chain model for rod type blocks in a rod‐coil diblock copolymer is implemented in the self‐consistent field theory (SCFT) formalism. A pseudo‐spectral method is used to solve for the single‐chain partition function of this copolymer system

Characterization of Interfacial Structure in Polymer-Fullerene Bulk Heterojunctions via 13C {2H} Rotational Echo Double Resonance NMR

July 13, 2018
Author(s)
Ryan C. Nieuwendaal, Dean M. DeLongchamp, Martin Heeney, Jan Hummelen, Chad R. Snyder, Ronald L. Jones, Sebastian Engmann, Lee J. Richter, Zhuping Fei, Alex Sieval
We introduce a new application of solid state NMR measurements towards characterizing the donor-acceptor interfaces within bulk heterojunction (BHJ) films. Rotational echo double resonance (REDOR) is used to measure dipolar couplings between 13C nuclei on

Glassy Phases in Organic Semiconductors

March 17, 2018
Author(s)
Chad R. Snyder, Dean M. DeLongchamp
Organic semiconductors may be processed from fluids using graphical arts printing and patterning techniques to create complex circuitry. Because organic semiconductors are weak van der Waals solids, the creation of glassy phases during processing is quite

Blade Coating Aligned, High-Performance, Semiconducting-Polymer Transistors

February 22, 2018
Author(s)
Lee J. Richter, Hyun W. Ro, Regis J. Kline, Daniel A. Fischer, Dean M. DeLongchamp, Lars Thomsen, Christopher McNeil, Dawei Wu, Maria Kaplan, Eliot H. Gann
Recent demonstration of mobilities in excess of 10 cm2V-1s-1 have energized research in solution deposition of polymers for thin film transistor applications. Due to the lamella motif of most soluble, semiconducting polymers, the local mobility is

Modeling the polarized X-ray scattering from periodic nanostructures with molecular anisotropy

December 1, 2017
Author(s)
Christopher D. Liman, Thomas A. Germer, Daniel F. Sunday, Dean M. DeLongchamp, Regis J. Kline
We discuss a new technique to measure molecular orientation in nanostructures using resonant soft X-rays. This technique is based on a variable angle transmission measurement called critical dimension X-ray scattering that enables the characterization of

Morphological characterization of fullerene and fullerene-free organic photovoltaics by combined real and reciprocal space techniques

May 26, 2017
Author(s)
Donglin Zhao, Qinghe Wu, Luping Yu, Harald Ade, Dean DeLongchamp, Lee J. Richter, Subhrangsu Mukherjee, Andrew Herzing
Morphology can play a critical role in determining function in organic photovoltaic (OPV) systems. Recently molecular acceptors have showed promise to replace¬ fullerene derivatives as acceptor materials in bulk heterojunction solar cells and have achieved

The dependence of electrical performance on structural organization in low mobility polymer field effect transistors

April 16, 2017
Author(s)
Emily G. Bittle, Hyun W. Ro, Chad R. Snyder, Sebastian Engmann, Regis J. Kline, Oana Jurchescu, Dean M. DeLongchamp, David J. Gundlach
Polymer semiconductors are contenders for use in printed, flexible electronics. Though organic electronic materials have been studied for many years, the physics of charge transport is still under investigation. This is in part due to the large variability

Reduced Bimolecular Recombination in Blade-Coated, High-Efficiency, Small-Molecule Solar Cells

March 22, 2017
Author(s)
Sebastian Engmann, Hyun W. Ro, Andrew A. Herzing, Dean M. DeLongchamp, Chad R. Snyder, Lee J. Richter, Adam J. Barito, David J. Gundlach
The full benefit of emerging solution deposited photovoltaic devices requires development of processes compatible with high speed manufacturing. Extensive studies of the lab-to-fab challenge have been performed on polymer donor based organic photovoltaics

In situ X-ray scattering studies of the influence of an additive on the formation of a low-bandgap bulk- heterojunction

February 21, 2017
Author(s)
Felicia A. Bokel, Lee J. Richter, Sebastian Engmann, Andrew Herzing, Brian A. Collins, Hyun W. Ro, Dean DeLongchamp
The evolution of the morphology of a high-efficiency, blade-coated, organic-photovoltaic (OPV) active layer containing the low band-gap polymer poly[(4,8-bis[5-(2-ethylhexyl)thiophene-2-yl]benzo[1,2-b:4,5-b']dithiophene)-2,6-diyl-alt-(4-(2-ethylhexanoyl)

Structure and Order in Organic Semiconductors

January 17, 2017
Author(s)
Chad R. Snyder, Dean M. DeLongchamp, Ryan C. Nieuwendaal, Andrew A. Herzing
Several techniques for characterizing semiconducting polymer order on different length scales are presented, including (1) differential scanning calorimetry (DSC), (2) solid state nuclear magnetic resonance spectroscopy (NMR), (3) transmission electron