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Search Publications by: Lee J Richter (Fed)

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Displaying 76 - 100 of 150

Formation of Silicon-Based Molecular Electronic Structures Using Flip-chip Lamination

August 11, 2009
Author(s)
Mariona Coll Bau, Lauren H. Miller, Lee J. Richter, Daniel R. Hines, Curt A. Richter, Christina A. Hacker
The use of organic molecules to impart electrical surface properties has been a subject of intense research not only from a fundamental perspective but for many technological applications. In particular, organic molecules have been proposed as active

Three-Dimensionally Structured CdTe Thin Film Photovoltaic Devices with Self-Aligned Back Contacts: Electrodeposition on Interdigitated Electrodes.

June 25, 2009
Author(s)
Daniel Josell, Carlos R. Beauchamp, Suyong S. Jung, Behrang H. Hamadani, Abhishek Motayed, Lee J. Richter, Maureen E. Williams, John E. Bonevich, Alexander J. Shapiro, Nikolai B. Zhitenev, Thomas P. Moffat
Cadmium-telluride photovoltaic cells were deposited on substrates patterned with two interdigitated electrodes. Deposition involved application of different potentials to the two electrodes in order to obtain a 3-d gradient of film properties within the

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

Scatterometry for in situ measurement of pattern reflow in nanoimprinted polymers

December 9, 2008
Author(s)
Heather J. Patrick, Thomas A. Germer, Yifu Ding, Hyun Wook Ro, Lee J. Richter, Christopher L. Soles
We use optical scatterometry to extract the time evolution of the profile of nanoimprinted lines in low and high molecular mass polymer gratings during reflow at the glass transition temperature. The data are obtained continuously during the anneal using a

Contact-induced crystallinity for high-performance soluble acene-based transistors and circuits

March 8, 2008
Author(s)
David J. Gundlach, James E. Royer, SK Park, Sankar Subramanian, Oana Jurchescu, Behrang H. Hamadani, Andrew Moad, Regis J. Kline, LC Teague, Oleg A. Kirillov, Curt A. Richter, Lee J. Richter, Sean R. Parkin, Thomas Jackson, JE Anthony
The use of organic materials presents a tremendous opportunity to significantly impact the functionality and pervasiveness of large-area electronics. Commercialization of this technology requires reduction in manufacturing costs by exploiting inexpensive

Contact Induced Crystallinity for High Performance Soluble Acene-Based TFTs

February 17, 2008
Author(s)
David J. Gundlach, James Royer, Behrang Hamadani, Lucile C. Teague, Andrew J. Moad, Oana Jurchescu, Oleg A. Kirillov, Lee J. Richter, James G. Kushmerick, Curt A. Richter, Sungkyu Park, Thomas Jackson, Sankar Subramanian, John E. Anthony
Organic electronics present a tremendous opportunity to significantly impact the functionality and pervasiveness of large-area electronics. However, the lack of low-temperature low-cost deposition and patterning techniques limits the potential for the

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

The Characterization of Silicon-Based Molecular Devices

September 30, 2007
Author(s)
Nadine Gergel-Hackett, Christina Hacker, Lee J. Richter, Oleg A. Kirillov, Curt A. Richter
In order to realize molecular electronic (ME) technology, an intermediate integration with more traditional silicon-based technologies will likely be required. However, there has been little effort to develop the metrology needed to enable the fabrication

Distinguishing Between Nonlinear Channel Transport and Contact Effects in Organic FETs

August 30, 2007
Author(s)
Behrang Hamadani, Jeremy LeBoeuf, R J. Kline, Iain McCulloch, Martin Heeney, Curt A. Richter, Lee J. Richter, David J. Gundlach
We investigate charge injection and transport in organic field-effect transistors fabricated by using poly(2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene) (pBTTT-C14) as the active polymer layer. We show that in high mobility devices where the

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

Characterization and Control of Lipid Layer Fluidity in Hybrid Bilayer Membranes

January 31, 2007
Author(s)
Neil A. Anderson, Lee J. Richter, John C. Stephenson, Kimberly A. Briggman
The main gel-to-liquid-crystal (LC) phase transition temperature, Tm, of the distal lipid layer in hybrid bilayer membranes (HBMs) under water was investigated using vibrational sum frequency spectroscopy (VSFS). VSFS has unique sensitivity to order

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

Optical Anisotropy of Semiconducting Single-Wall Carbon Nanotubes

January 1, 2007
Author(s)
Jeffrey Fagan, Erik K. Hobbie, Jeffrey R. Simpson, Lee J. Richter, Idan Mandelbaum, Vardhan Bajpai, Derek L. Ho, Barry J. Bauer, Angela HightWalker, Ryan Raffaelle
We measure the full optical anisotropy of individual semiconducting single-wall carbon nanotubes (SWNTs). Dispersion of aligned SWNTs in stretched polymer films is confirmed with small-angle scattering and near-infrared fluorescence spectroscopy. By