This dissertation describes the relationship between the surface chemistry of colloidal semiconductor nanocrystals (quantum dots, QDs) and their optoelectronic properties, such as photoluminescence and degree of quantum confinement. We primarily focus our efforts on one particular subset of ligands known to couple strongly to the inorganic core of the QD...
Climate change may be one of the most important puzzles the world has attempted to solve and one of the greatest challenges in this area is to improve our understanding of how atmospheric aerosol particles impact climate processes. We seek to overcome this challenge by focusing on the chemistry and...
Heterogeneous catalysts play a prominent role in our society, used in applications that range from the production of plastics to the catalytic cracking of crude oil. Industrial catalysts are typically made of mixed metal oxides or nanosized metal particles deposited on high surface area supports. Industrially relevant catalytic materials are...
Ultrafast spectroscopy offers an unprecedented view on the dynamic nature of chemical reactions. From charge transfer in semiconductors to folding and isomerization of proteins, these all important processes can now be monitored and in some instances even controlled on real, physical timescales. One of the biggest challenges of ultrafast science...
Halide perovskites, AMX3 (A = monocation, B = Ge, Sn, or Pb, and X = halogen), present a versatile class of solution-processable semiconductors made from earth abundant materials with outstanding electrical and optical properties. Their solar cell efficiencies have dramatically increased from ~9% to ~22% in less than five years...
With the dual challenges of meeting global energy demand and mitigating anthropogenic climate change, significant effort is being applied to generating power from renewable sources. The dye-sensitized solar cell (DSC) is a photovoltaic technology capable of generating electricity from sunlight, but suffers losses in efficiency due to deleterious electron transfer...
Organic photovoltaics (OPVs) are an attractive solar energy technology for low-current applications. Herein is described the supramolecular design and methodology to manipulate intermolecular interactions in order to create an active layer in OPVs devices composed of crystalline and amorphous donor-acceptor domains, which has been proposed as the ideal morphology for...
Raman spectroscopy is an established and versatile molecular sensing technique, but it is limited by its modest chemical sensitivity. Surface-enhanced Raman spectroscopy (SERS) can amplify otherwise weak normal Raman signals up to nine to ten orders of magnitude, giving rise to its application in many molecular sensing problems, including those...
Interprotein electron transfer (ET) occupies a central role in both chemistry and biology, as it is important in a variety of functions including cellular respiration, metabolism, and energy transduction during photosynthesis. Consequently, understanding the protein-protein recognition and docking that controls interprotein ET is an important field of scientific research.
One...
Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for characterizing molecular systems. It combines the chemical selectivity of vibrational spectroscopy with plasmonic signal enhancement to achieve the ultimate limit of detection--a single molecule. By overcoming the effects of ensemble averaging, single molecule SERS (SMSERS) probes distributions in molecular interactions and...