Wong, CathyWilson, Kelly2021-04-272021-04-272021-04-27https://hdl.handle.net/1794/26171Single-shot transient absorption (SSTA) spectroscopy overcomes the limitations of conventional transient absorption (TA) instruments by spatially encoding the pump-probe time delay into the probe spatial profile. This enables the measurement of excited state dynamics of systems that evolve on time scales below the acquisition time of typical TA instruments. This dissertation describes techniques used to spatially encode the time delay and design principles that must be followed to accurately measure the excited state dynamics. Presented herein is the design and implementation of a homebuilt broadband SSTA instrument with a 60-ps time delay range and 100-nm spectral range capable of acquiring a transient spectrum within a few seconds. This instrument achieves the largest time delay range of any previously reported SSTA instrument. This range is achieved through the use of a spatial light modulator which reshapes each beam to a flat-top profile, enabling a uniform excitation density and maintaining a good signal-to-noise ratio throughout the spatially encoded delay. A homebuilt, user-friendly software controls a range of scientific equipment, acquires and processes data at high acquisition rates, and corrects for evolving scatter and photoluminescence during SSTA measurements. Techniques are introduced that calibrate the spatial time delay and spectral axes of the instrument and correct for deviations in the signal caused by variations in the pump profile. Presented SSTA measurements of chemical systems exemplify research questions in materials science that can only be addressed using SSTA. First-ever SSTA measurements during film formation reveal an intermediate, highly fluorescent aggregates of pseudoisocyanine iodide with different excited state dynamics from the fully formed film. Measurements of hybrid organic-inorganic perovskite nanocrystals (NCs) reveal a transient spectral feature that reports on the surface quality of growing NCs. Preliminary TA measurements of organic electron donor:acceptor systems are presented and will direct future in situ SSTA measurements during thin film formation and thermal annealing. This instrument is capable of measuring the excited state dynamics of evolving systems like these and, for the first time, will provide insight into the relationship between intermediate excited state dynamics and other structural and photophysical characteristics. This dissertation includes previously published and unpublished co-authored material.en-USAll Rights Reserved.In situTransient absorptionUltrafast spectroscopyElectronic Thesis or Dissertation