He earned his doctoral degree (1979) in Physical Chemistry from the Bombay University and carried out postdoctoral research at Boston University (1979University ( -1981 and University of Texas at Austin (1981Austin ( -1983. He joined Notre Dame in 1983 and initiated a successful research project on utilizing semiconductor nanostructures for light energy conversion. His major research interests are in three areas: (1) to understand interfacial processes and catalytic reactions at nanostructured semiconductor interface, (2) to develop semiconductor hybrid assemblies for solar cells and solar fuels, and (3) carbon nanostructure architectures for energy conversion and storage. He has authored more than 350 peer-reviewed journal papers, review articles, and book chapters with more than 20000 citations. He has also edited three books in the area of nanoscale materials.Kevin Tvrdy (far left) received his Bachelor's degree in Chemistry from the University of Nebraska in 2005, after which he worked for one year at Streck Laboratories as an R&D technician. He is currently pursuing his doctoral degree at the University of Notre Dame in the Department of Chemistry and Biochemistry under the direction of Prashant V. Kamat. His current research centers on the application of ultrafast spectroscopic measurements to better understand and improve upon electron transfer phenomena in photovoltaic devices. In his free time, Kevin enjoys spending time with his wife Jessica outdoors. David R. Baker (far right) is a Ph.D. candidate in the Department of Chemical and Biomolecular Engineering at the University of Notre Dame, and Radiation Laboratory. He earned his Bachelor's degree in Chemical Engineering at the University of Washington in 2006, where he researched interfacial water phenomena and methylotrophic bacterial populations. His current research focuses on electrode-electrolyte interactions and developing nanoarchitectures within quantum dot solar cells. He has interned with the Jet Propulsion Laboratory and the United States Department of State. Emmy J. Radich (not pictured) is a P h.D. student in the Department of Chemical and Biomolecular Engineering at the University of Notre Dame where she works under the guidance of Prashant Kamat in the Notre Dame Radiation Laboratory. Her current focus is on carbon-based nanostructured composite materials for energy applications. Emmy earned her Bachelor's and Master's degrees in Chemical Engineering from the Dave C. Swalm School of Chemical Engineering at Mississippi State University. She also spent four years working at RespirTek, Inc., a commercial bioenvironmental laboratory. Emmy's research interests are diverse, with past projects focusing on biofuels synthesis, gas hydrates, anaerobic digestion, and novel bioremediation strategies. Emmy has also worked in various government and industrial positions ranging from groundwater assessment/ remediation regulator to a refinery process engineer to laboratory director. convert light energy into electricity. 7-10 Unlike solid state photovolt...

TiO2 nanotube arrays and particulate films are modified with CdS quantum dots with an aim to tune the response of the photoelectrochemical cell in the visible region. The method of successive ionic layer adsorption and reaction facilitates size control of CdS quantum dots. These CdS nanocrystals, upon excitation with visible light, inject electrons into the TiO2 nanotubes and particles and thus enable their use as photosensitive electrodes. Maximum incident photon to charge carrier efficiency (IPCE) values of 55% and 26% are observed for CdS sensitized TiO2 nanotube and nanoparticulate architectures respectively. The nearly doubling of IPCE observed with the TiO2 nanotube architecture is attributed to the increased efficiency of charge separation and transport of electrons.

The presence of sulfide/polysulfide redox couple is crucial in achieving stability of metal chalcogenide (e.g., CdS and CdSe)-based quantum dot-sensitized solar cells (QDSC). However, the interfacial charge transfer processes play a pivotal role in dictating the net photoconversion efficiency. We present here kinetics of hole transfer, characterization of the intermediates involved in the hole oxidation of sulfide ion, and the back electron transfer between sulfide radical and electrons injected into TiO(2) nanoparticles. The kinetic rate constant (10(7)-10(9) s(-1)) for the hole transfer obtained from the emission lifetime measurements suggests slow hole scavenging from CdSe by S(2-) is one of the limiting factors in attaining high overall efficiency. The presence of the oxidized couple, by addition of S or Se to the electrolyte, increases the photocurrent, but it also enhances the rate of back electron transfer.

Despite its importance in dictating electrochemical reversibility and cell chemistry kinetics, the solid electrolyte interphase (SEI) on graphitic anodes remains the least understood component in Li ion batteries due to its trace presence, delicate chemical nature, heterogeneity in morphology, elusive formation mechanism, and lack of reliable in situ quantitative tools to characterize it. This work summarizes our systematic approach to understand SEI live formation, via in situ electrochemical atomic force microscopy, which provides topographic images and quantitative information about the structure, hierarchy, and thickness of interphases as function of electrolyte composition. Complemented by an ex situ chemical analysis, a comprehensive and dynamic picture of interphase formation during the first lithiation cycle of the graphitic anode is described. This combined approach provides an in situ and quantitative tool to conduct quality control of formed interphases.

Ligand exchange with 3-mercaptopropionic acid (MPA) has been successfully used to tune the emission intensity of trioctylphosphineoxide/dodecylamine-capped CdSe quantum dots. Addition of 3-mercaptopropionic acid (MPA) to CdSe quantum dot suspension enhances the deep trap emission with concurrent quenching of the band edge emission. The smaller sized quantum dots, because of larger surface/volume ratio, create a brighter trap emission and are more easily tuned. An important observation is that the deep trap emission which is minimal after synthesis is brightened to have a quantum yield of 1-5% and can be tuned based on the concentration of MPA in solution with the quantum dots. Photoluminescence decay and transient absorption measurements reveal the role of surface bound MPA in altering the photophysical properties of CdSe quantum dots.