SPECTROSCOPIC INVESTIGATIONS OF ELECTRON TRANSFER PROCESSES AT DYE-SENSITIZED PHOTOELECTRODES Public Deposited

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Last Modified
  • March 20, 2019
Creator
  • Han, Yejee
    • Affiliation: College of Arts and Sciences, Department of Chemistry
Abstract
  • Over the last century, energy demands have grown quickly due to an increasing global population. To limit our dependence on fossil fuels, it is desirable to seek environmentally clean, alternative energy resources. Solar energy is expected to be a good, renewable energy candidate because of environmental protection. Crystalline silicon-based photovoltaic devices used most frequently, with solar to electricity conversion efficiencies of approximately 25%. However, high cost and complicated fabrication processes excluded conventional silicon-based solar cells from domestic and other commercial applications. Dye sensitized solar cells (DSSCs) provide a promising low-cost technology for capturing solar energy. Until recently, researchers have been focused on n-type DSSCs that use a wide-band-gap n-type semiconductor oxide such as TiO2 or ZnO. Even though comparably fewer studies have examined p-type semiconductors, scientific interest has quickly grown to understand the factors that control the rate of hole photoinjection and to design more efficient systems. Core-shell nanoporous electrode has been used in dye-sensitized solar cells (DSSCs) and dye-sensitized photoelectrosynthesis cells (DSPECs) as one of the most effective strategies providing energy barrier of recombination process. We have used a core/shell consisting of an inner core of a SnO2 and a thin outer shell of TiO2 prepared by use of atomic layer deposition (ALD), where the band potential of the shell is more negative than that of the core. Transient absorption spectroscopy was used to investigate the interfacial charge recombination dynamics to elucidate the dominated mechanism between tunneling and shell-localized BET in different shell thickness architecture. This study will enable us to use as a quantitative guide for ideal core/shell electrodes in optimizing the most efficient solar cells.
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Rights statement
  • In Copyright
Advisor
  • Schauer, Cynthia
  • Dempsey, Jillian
  • Meyer, Gerald
Degree
  • Master of Arts
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2017
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