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Search Publications by: Dean DeLongchamp (Fed)

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Displaying 26 - 50 of 118

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

Morphology-insensitive Performance Facilitates Transition from Spin-Coating to Roll-to-Roll Coating For High-Performance, Solution-Processed Solar Cells

August 2, 2016
Author(s)
Lee J. Richter, Jonathan Downing, Sebastian Engmann, Hyun W. Ro, Andrew A. Herzing, Dean M. DeLongchamp, Subhrangsu Mukherjee, Harald Ade, Maged Addelsamie, Aram Amassian, Yuhang Liu, He Yan
Solution processing via roll-to-roll (R2R) coating promises a low cost, low thermal-budget, sustainable revolution for the production of solar cells. Yet virtually all high performance solution processed research cells have been demonstrated by spin

Structural control of mixed ionic and electronic transport in conducting polymers

April 17, 2016
Author(s)
Jonathan Rivnay, Sahika Inal, Brian Collins, Michelle Sessolo, Eleni Stavrindou, Christopher Tassone, Dean DeLongchamp, George Malliaras
Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate), PEDOT:PSS, has been utilized for over two decades as a stable, solution-processable conductor. While electrical properties have been the subject of intense materials investigation, recent

Real-time Photoluminescence Studies of Thin Film Formation in Organic Solar Cells

February 29, 2016
Author(s)
Sebastian Engmann, Felicia A. Bokel, Hyun W. Ro, Dean M. DeLongchamp, Lee J. Richter
We present a method to study the structural evolution of organic bulk-heterojunctions via real-time, in-situ, steady state photoluminescence (PL). In-situ PL, in combination with real-time transmission and reflection measurements, allowed us to

The Structural Origin of Electron Injection Enhancements with Fulleropyrrolidine Interlayers

February 25, 2016
Author(s)
Lee J. Richter, Hyunbok Lee, Christopher McNeil, Eliot Gann, Lars Thomsen, S. Park, J. Jeong, Z. A. Page, Egle Puodziukynaite, Todd Emrick, Alejandro Briseno, John C. Stephenson, Dean M. DeLongchamp
Market demand for ubiquitous, increased functionality products at low cost (the internet of things) is spurring development in additive, solution processing of electronic devices. Performance in thin-film functional devices, be they transistors, diodes, or

The Impact of the Crystallite Orientation Distribution on Exciton Transport in Donor-Acceptor Conjugated Polymers

December 30, 2015
Author(s)
Alexander L. Ayzner, Jianguo Mei, Anthony Appleton, Dean DeLongchamp, Alexandre Nardes, Stephanie Benight, Nikos Kopidakis, Michael F. Toney, Zhenan Bao
Conjugated polymers are widely used materials in organic photovoltaic devices. Owing to their extended electronic wavefunctions, they often form semicrystalline thin films. Although it is known that the polymer crystal orientation plays a large role in

Classification of Semiconducting Polymeric Mesophases to Optimize Device Post-Processing

August 17, 2015
Author(s)
Chad R. Snyder, Regis J. Kline, Dean M. DeLongchamp, Ryan C. Nieuwendaal, Lee J. Richter, Martin Heeney, Iain McCulloch
Semiconducting polymers form a variety of phases and mesophases that respond differently to post-deposition solvent or thermal treatments. Here it is shown that classification of these materials into their appropriate mesophases can be a useful tool to

Real-time x-ray scattering studies of film formation in high performing small-molecule organic solar cells

May 23, 2015
Author(s)
Sebastian Engmann, Felicia A. Bokel, Andrew Herzing, Hyun W. Ro, Dean DeLongchamp, Lee J. Richter, Claudio Girotto, Bruno Caputo
We have studied the influence of the additive diiodoctane on the formation dynamics of high performance bulk heterojunction (BHJ) films based the small molecule donor 7,7'-(4,4bis(2- ethylhexyl)-4H-silolo[3,2-b:4,5-b']dithiophene-2,6-diyl)bis(6-fluoro-5-(5

Dry graphene transfer print to polystyrene and ultra-high molecular weight polyethylene ? detailed chemical, structural, morphological and electrical characterization

May 17, 2015
Author(s)
Evegeniya Lock, Dean DeLongchamp, Scott Schmucker, Blake Simpkins, Matthew Laskoski, Shawn Mulvaney, Daniel R. Hines, Mira Baraket, Sandra Hernandez, Jeremy Robinson, Paul Sheehan, Cherno Jaye, Daniel A. Fischer, Scott Walton
In this paper we apply a transfer print approach that relies on differential adhesion to remove graphene from Cu foil to polystyrene (PS) and ultra-high molecular weight polyethylene (UHMW PE) without etching of the metal foil. The polymer surfaces are

Direct correlation of charge transfer absorption with molecular donor:acceptor interfacial area via photothermal deflection spectroscopy

April 9, 2015
Author(s)
Lee J. Richter, Dean M. DeLongchamp, Natalie Stingelin, Alberto Salleo, Martin Heeney, Aram Amassian, John deMello, James Bannock, Fiona H. Scholes, Scott Watkins, Zhuping Fei, Koen Vandewal
ABSTRACT: Here, we show that the Charge Transfer (CT) absorption signal in bulk (BHJ) solar cell blends, measured by photothermal deflection spectroscopy (PDS), is directly proportional to the density of molecular donor/acceptor interfaces. Since the

Poly(sulfobetaine methacrylate)s as Electrode Modifiers for Inverted Organic Electronics

January 14, 2015
Author(s)
Hyunbok Lee, Egle Puodziukynaite, Dean DeLongchamp, Todd Emrick, Alejandro Briseno
We demonstrate the use of poly(sulfobetaine methacrylate) (PSBMA), and its pyrene-containing copolymer, as solution-processable work function reducers for inverted organic electronic devices. A notable feature of PSBMA is its orthogonal solubility relative

Interrogating the Carbon and Oxygen K-edge NEXAFS of a CO2-dosed Hyperbranched Aminosilica

December 19, 2014
Author(s)
Laura Espinal, Martin L. Green, Dean M. DeLongchamp, Watcharop Chaikittisilp, Jarod C. Horn, Miles Sakwa-Novak, Cherno Jaye, Daniel A. Fischer, Nicholas Brunelli, Christopher Jones
Near edge x-ray absorption fine structure (NEXAFS) spectroscopy was used to study the adsorption of CO2 in a hyperbranched aminosilica (HAS) compound, a porous solid state material with great potential for carbon capture applications. After dosing a