Jeff UrbanFacility Director, Inorganic Nanostructures
I am interested in the development of new materials and measurement tools for solid-state energy storage and conversion applications. One central topical area of interest involves investigating transport at the organic-inorganic interface. This marriage of "hard" and "soft" materials presents an interesting contrast of transport modalities, bond strengths, mechanical properties, and the like.
The synthesis, assembly, characterization, measurement, and modeling of composite materials composed of both "hard" inorganic nanocrystalline elements and "soft" organic polymers and small molecules is one of my main research foci. If understanding and design could be applied to these materials, the ability to capture both the advantages of polymers and nanocrystals in one material presents many exciting opportunities for basic research and applications.
On the measurement side, I am interested in studying the processes of charge and heat transport in solid-state devices using electronic and optical probes. Most of the intuition developed for these materials is rooted in continuum transport models, however, many interesting questions emerge at the nanoscale: what happens to heat transport when the active layers are less than an average mean free path? How does the physics of charge transport change in a p-n junction when the system size is smaller than a typical depletion length? Can creating chemically defined channels modify traditional tradeoffs between permeability and selectivity in dense materials?
Jeff Urban's CV [pdf]
- Thermoelectrics and the isolation of charge and heat flows
- Studying heat transport in quantum dot solid films
- Developing new thermoelectric composite materials
- Exploring small molecule effects on composite transport
- Developing optical and electrical probing of activated transport processes under thermal bias
- Photovoltaics and Photoelectrochemical Processes
- Working on unconventional materials for photon recycling
- Developing new encapsulants with enhanced barrier properties
- Manipulating interfacial effects to drive classically 'difficult' electrochemical events
- Gas Transport and Storage
- Developing new nanocrystal-polymer composites for H2 and CO2 storage
- Understanding the size-dependent phase transitions associated with chemical capture of gases in solids
- Designing new hybrid polymer-nanocrystal materials with optimized permeability and selectivity
- Electrochemical Energy Storage
- Developing redox-switchable nanocrystalline systems for high-power applications
- Developing test cells enabling optical and electrical probing of electrode-electrolyte interfacial properties
- Synthesis of programmable carbon nanomaterials for electrical interfacing in electrode materials
- "Mixing behavior of the thermoelectric properties of conducting polymer/nanocrystal composites," Nelson E. Coates, Shannon K. Yee, Kevin C. See, *Rachel A. Segalman, and, *Jeffrey J. Urban, submitted (2011).
- “Air-stable magnesium nanocomposites provide rapid and high-capacity hydrogen storage without using heavy-metal catalysts,” Ki-Joon Jeon, Hoi Ri Moon, Anne M. Ruminski, Bin Jiang, Christian Kisielowski, and *Jeffrey J. Urban, Nature Materials, 10(4), 286-290 (2011).
- “Water-processable polymer-nanocrystal hybrids for thermoelectrics,” Kevin C. See, Joseph P. Feser, Cynthia E. Chen, Arun Majumdar, *Jeffrey J. Urban, and *Rachel A. Segalman, Nano Lett., 10(11), 4664-4667 (2010).
- “Universal and solution-processable precursor to bismuth chalcogenide thermoelectrics”, Robert Y. Wang, Joseph P. Feser, Xun Gu, Kin Man Yu, Rachel A. Segalman, Arun Majumdar, *Delia J. Milliron, and *Jeffrey J. Urban, Chem. Mater., 22(6), 1943-1945 (2010).
- “Synergism in binary nanocrystal superlattices leads to enhanced p-type conductivity in self-assembled PbTe/Ag2Te thin films,” *Jeffrey J. Urban, Dmitri V. Talapin, Elena V. Shevchenko, Cherie R. Kagan, and *C.B. Murray, Nature Materials 6(2) 115-121 (2007).
A complete list of Jeff Urban's publications can be found on his full CV.
Postdoctoral Studies in Synthesis and Measurements of Nanocrystal Transistors, Thermoelectrics, and Photovoltaics with Professor Christopher B. Murray, University of Pennsylvania
Graduate Studies in Synthesis and Physical Characterization of Transition Metal Oxide Nanostructures with Professor Hongkun Park, Harvard University