Quantum mechanical phenomena are playing tremendous roles in many areas of chemistry and materials science research. In recent years, the potential role of coupling between electronic and vibrational degrees of freedom in photochemical processes has been widely researched. Despite its potential to improve molecular technologies, the lack of studies focusing...
Organic photovoltaics offer an opportunity to make solar cells more affordable and widely accessible using cheap, solution-processable light-absorbing layers. In order to realize new technologies, a fundamental understanding of organic chromophore photophysics is required to overcome efficiency limitations. Throughout this doctoral work, I investigated the kinetic and physical characteristics of...
This thesis contains two research projects. The first research project examined the coherent nature of electron transfer in two donor-acceptor dyads – one single acceptor control compound and one dual acceptor molecule of interest. Using transient absorption spectroscopy in the ultraviolet/visible/near-infrared and mid-infrared regions, magnetic field effect experiments, and theoretical...
Thermoelectric devices utilize semiconducting n-type and p-type thermoelectric materials to convert heat into electricity. Despite their promise for deep space power generation or waste heat recovery, most high-performing thermoelectric materials reported in literature are absent in practical applications - partially due to inconsistent synthesis and poor mechanical performance. This work...
Plasmonic nanoparticles have very large absorption cross sections and can concentrate the local density of photon states on the nano scale. When they are coupled to molecules or semiconductor nanocrystals and form different hybrid nanostructures, various light-matter interaction processes can be significantly enhanced or manipulated, including optical responses like fluorescence...
Creating sustainable and clean sources of energy is an outstanding problem of importance for the current generation of scientists to solve. Organic photovoltaics (OPVs) are a promising renewable energy source but require improvements to their architectures and better fundamental understanding of the effects of organic chromophore morphology on the resulting...
Semiconductor nanocrystals possess unique photophysical properties that make them desirable for many optoelectronic applications such as photovoltaics, LEDs, and quantum computing. When the size of a semiconductor is reduced to below the excitonic Bohr radius of the material, its carriers becomes quantum confined resulting in drastic changes to optical, electronic,...
This dissertation explores ways to utilize physical parameters at the nanoscale interface to control the properties of mixed-dimensional heterojunctions (MDHJs). MDHJs combine the desirable properties of different classes of low-dimensional nanomaterials (materials that are quantum confined in at least one dimension). While MDHJs have achieved superlative performance for a variety...
Metal halide perovskites have recently emerged as one of the most promising active layers in solar cells for their high power conversion efficiency (>25%) and ease of synthesis and deposition. Spatial heterogeneity is inevitable with current fabrication methods for both monocrystalline and polycrystalline perovskite thin films and crystals. The morphology-dependent...
This work examines important heterogeneous processes of organic molecules on surfaces, in the contexts of atmospheric and indoor environments. In large forest ecosystems, biogenic secondary organic aerosols (SOAs) constitute a dominant fraction of organic particulate matter in the atmosphere. The formation of SOAs starts from the emission of volatile organic...