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Search Publications by: Lee J Richter (Fed)

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Displaying 26 - 50 of 150

Efficient upgrading of CO to C3 fuel using asymmetric C-C coupling active sites

November 29, 2019
Author(s)
Lee J. Richter, Ahmad R. Kirmani, Xue Wang, Wang Ziyuan, Dinh Cao-Thang, Li Jun, Nam Dae-Hyun, Li Fengwang, Huang Chun-Wei, Tan Chih-Shan, Chen Zitao, Chi Miaofang, Gabardo M. Christine, Seiifitokaldani Ali, Todorovic Petar, Proppe Andrew, Pang Yuanjie, wang yuhang, Ip H. Alexander, Shen-Chuan Lo, shana O. kelley, David Sinton, Edward H. Sargent, Tao-Tao Zhuang, Benjamin Scheffel
The electroreduction of C1 feedgas to high-energy-density fuels provides an attractive avenue to the storage of renewable electricity. Much progress has been made to improve selectivity to C1 and C2 products, however, the selectivity to desirable high

Crystal Orientation Drives the Interface Physics at 2/3-Dimensional Hybrid Perovskites

September 9, 2019
Author(s)
Lee J. Richter, Ahmad R. Kirmani, Marine E. Bouduban, Valentine I. Queloz, Valentina M. Caselli, Kyung T. Cho, Sanghyun Paek, Cristina Roldan-Carmona, Jacques E. Moser, Tom J. Savenije, Mohammad K. Nazeeruddin, Giulia Grancini
Combining halide perovskites with tailored dimensionality into two/three-dimensional (2D/3D) systems has revealed a powerful strategy to boost the performances of perovskite photovoltaics (PVs). Despite recent advances, a clear understanding of the

Morphology of a thermally stable small molecule OPV blend comprising a liquid crystalline donor and fullerene acceptor

June 4, 2019
Author(s)
Alexander J. Bourque, Sebastian Engmann, Allison Fuster, Chad R. Snyder, Lee J. Richter, Paul B. Geraghty, David J. Jones
Recently organic photovoltaic (OPV) devices comprising the small molecule liquid-crystalline donor, benzodithiophene-quaterthiophene-rhodanine (BQR), were demonstrated to achieve high performance when thermally processed, avoiding the need for slow-drying

Stable Postfullerene Solar Cells via Direct C-H Arylation Polymerization. Morphology-Performance Relationships

May 16, 2019
Author(s)
Subhrangsu Mukherjee, Thomas Aldrich, Weigang Zhu, Lee J. Richter, Eliot Gann, Dean DeLongchamp, Antonio Facchetti, Ferdinand Melkonyan, Tobin Marks
The scope of the environmentally benign direct C-H arylation polymerization (DARP) process is validated and significantly extended in the synthesis of a high-performance benzodithiophene- based copolymer series, PBDT(Ar)-FTTE, with previously untested and

In Situ Back-Contact Passivation Improves Photovoltage and Fill Factor in Perovskite Solar Cells

February 10, 2019
Author(s)
Lee J. Richter, Ahmad R. Kirmani, Furui Tan, Hairen Tan, Wei Mingyang, Makhsud I. Saidaminov, Mengxia Liu, Mei Anyi, Peicheng Li, Chih-Shan Tan, Xiwen Gong, Yongbiao Zhao, Ziru Huang, James Z. Fan, Rafael Quintero-Bermudez, Kim Junghwan, Yicheng Zhao, Oleksandr Voznyy, Zheng-Hong Lu, Weifeng Zhang, Edward H. Sargent, Bowen Zhang, Yueye Gao, Feng Zhang
Organic–inorganic hybrid perovskite solar cells (PSCs) have seen a rapid rise in power conversion efficiencies in recent years; however, they still suffer from interfacial recombination and charge extraction losses at interfaces between the perovskite

Higher Order Effects in Organic LEDs with Sub-bandgap Turn-on

January 16, 2019
Author(s)
Sebastian Engmann, Adam J. Barito, Emily Bittle, Chris Giebink, Lee J. Richter, David J. Gundlach
Spin-dependent nonlinear processes in organic materials such as singlet-fission and triplet- triplet annihilation could increase the performance for photovoltaics, detectors, and light emitting diodes. Rubrene/C60 light emitting diodes exhibit a distinct

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

SEIRAS Study of Chloride Mediated Polyether Adsorption on Cu

August 31, 2018
Author(s)
Thomas P. Moffat, Daniel Josell, Lee J. Richter
Surface enhanced infrared absorption spectroscopy (SEIRAS) was used to examine the co- adsorption of a selection of polyethers with Cl- under conditions relevant to superconformal Cu electrodeposition in CuSO4-H2SO4 electrolytes. In 0.1 mol/L H2SO4 a

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

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

Simple Transfer from Spin Coating to Blade Coating Through Processing Aggregated Solutions

September 22, 2017
Author(s)
Jeff L. Hernandez, Nabankur Deb, Rylan M. Wolfe, Chi K. Lo, Sebastian Engmann, Lee J. Richter, John R. Reynolds
To develop an understanding of the effect spin coating or blade coating have on the morphology of polymer:fullerene thin films for organic solar cells, we have investigated the morphology of poly[5-(2-hexyldecyl)-1,3-thieno[3,4-c]pyrrole-4,6-dione-alt-5,5-

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

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)

Film morphology evolution during solvent vapor annealing of highly efficient small molecule donor/acceptor blends

September 15, 2016
Author(s)
Sebastian Engmann, Hyun W. Ro, Andrew Herzing, Chad R. Snyder, Lee J. Richter, Paul Geraghty, David Jones
Solution-processable small molecule photovoltaics based on the novel molecular donor, benzodithiophene terthiophene rhodamine (BTR), recently have shown maximum power conversion efficiencies above 8% for active layer thicknesses up to 400 nm, using post

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

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

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

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