Contact Information
pcunni1@umbc.edu
Physics, Rm 409;
Labs 406 C&D
External Links
Hayden Research Group
THz Polymers Wiki
NSF STC-MDITR
MDITR Wiki
Curriculum Vitae
Research Summary
Photograph by Tim
Ford
Paul D Cunningham
Title
Graduate Research Assistant,
Dept. of Physics, Univ. of Maryland Baltimore Co.
Education
Ph.D. Physics - University of Maryland Baltimore County, expected 2009
Previous ExperienceDuring my undergraduate studies, I researched colossal magnitoresistance in manganite thin films under the mentoring of Dr. M. Raj Rajeswari and the Materials Research Group. Prior to entering UMBC, I worked for a year with the Reliability Branch of the Logistics Analysis Division of the US Army Materiel Systems Analysis Activity performing Physics-of-Failure analysis at Aberdeen Proving Ground. Research InterestsTime-resolved THz studies  Terahertz radiation, which lies in the far-infrared, corresponds to collective oscillations in crystals and organic molecules. This characteristic combined with its low, non-ionizing, energy makes THz spectroscopy well suited for security, biomedical, and other spectroscopic applications. Time-resolved THz spectroscopy, i.e. optical-pump THz-probe, is a special case of ultrafast pump-probe spectroscopy where the THz (low energy) probe does not perturb the system. The high frequency, as compared to DC methods, is sensitive to carrier transport over the nanoscale. Coherent methods, such as the electro-optic effect, allow for the detection of THz electric field transients. The fact that the inverse of carrier scattering times correspond to THz frequencies makes THz radiation well suited for studying the evolution of the dielectric properties of a material after excitation. Such studies can aid in determining how charge generation and transport in nanocrystalline materials differ from their bulk counterparts, examining quasi-particle dynamics in superconductors, exploring multi-exciton generation in quantum confined structures, and elucidating charge generation and transport in organic crystals and polymers.
Charge transport in organic materials
 Organics present a low-cost alternative to inorganic materials for photovoltaic, light-emitting diode, and opto-electronic applications with the benefits of roll-to-roll fabrication and tunable properties. Despite a wealth of research and commercially available devices, fundamental properties such as primary photogenerated products, photo-induced charge generation and subsequent charge transport are not yet fully understood. These intrinsic properties are further convoluted by their dependence on morphology and processing conditions. Systematic studies utilizing a variety of techniques are necessary to elucidate the nature of these properties that impact device performance. Electro-optic polymers for THz applications
 Nonlinear optical guest-host polymer systems are a promising class of materials for opto-electronic devices e.g. electo-optic modulators for photonics-based telecommunications owing to their wavelength tunable properties and large nonlinearity. These systems also present promise as broadband sources and sensors for THz radiation due to their low loss and good phase-matching characteristics. Potential applications include nondestructive device evaluation, noninvasive imaging for medical and security application, chemical sensing, chemical fingerprinting, and time-resolved studies of photoconductive material systems.
Publications
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