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Search Publications by: John C. Stephenson (Assoc)

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Displaying 1 - 25 of 36

Polarization Dependence of Charge Conduction in Conjugated Polymer Films Investigated with Time- Resolved Terahertz Spectroscopy

March 6, 2020
Author(s)
Timothy J. Magnanelli, Sebastian Engmann, Jared K. Wahlstrand, John C. Stephenson, Lee J. Richter, Edwin J. Heilweil
We interrogate polarization anisotropy associated with charge conduction in films of the block co polymer PCDTPT, consisting of alternating cyclopenta dithiophene (donor) and thiadiazolo pyridine (acceptor) units with respect to sample morphology. Film

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

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

Determination of Lipid Phase Transition Temperatures in Hybrid Bilayer Membranes

September 9, 2006
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 lipid monolayers in hybrid bilayer membranes (HBMs) was investigated using vibrational sum frequency spectroscopy (VSFS). The unique sensitivity of VSFS to probe order/disorder

Correlation of Molecular Orientation with Adhesion at Polystyrene/Soild Interfaces

September 1, 2002
Author(s)
P T. Wilson, Lee J. Richter, William E. Wallace, Kimberly A. Briggman, John C. Stephenson
Vibrationally resonant sum-frequency generation (VR-SFG) has been used to characterize the molecular orientation of the phenyl groups at the interface between polystyrene (PS) films and surface-modified glass substrates. Both the interface structure and

Absolute Molecular Orientational Distribution of the Polystyrene Surface

April 1, 2001
Author(s)
Kimberly A. Briggman, John C. Stephenson, William E. Wallace, Lee J. Richter
Vibrationally-resonant sum frequency generation (VR-SFG) has been used to study the absolute molecular orientational distribution of the pendant phenyl groups at the free surface of polystyrene (PS) thin films on oxidized Si substrates. Characterization of

Sum Frequency Spectroscopy Studies of Adsorption of Additives on Metal/Electrolyte Interfaces

November 1, 2000
Author(s)
Clayton S. Yang, Lee J. Richter, Kimberly Briggman, John C. Stephenson, Thomas P. Moffat, Gery R. Stafford
In situ and ex situ VR-SFG studies of mercaptopropylsulfonate (MPSA) molecules adsorbed on metal/electrolyte interfaces prove the molecular conformation is sensitive to hydration. MPSA catalyses electrodeposition of copper interconnection for semiconductor

Vibrationally-Resolved Sum-Frequency Generation With Broad Bandwidth Infrared Pulses

October 15, 1998
Author(s)
Lee J. Richter, T Petralli-Mallow, John C. Stephenson
We present a novel procedure for vibrationally-resolved sum-frequency generation (SFG) in which a broad-bandwidth IR pulse is mixed with a narrow-bandwidth visible pulse. The resultant SFG spectrum is dispersed with a spectrograph and detected in parallel