Gamelin, Daniel RAraujo, Jose Juan2020-08-142020-08-142020-08-142020Araujo_washington_0250E_21427.pdfhttp://hdl.handle.net/1773/45900Thesis (Ph.D.)--University of Washington, 2020For the past few decades, semiconductor nanocrystals (NCs) have been the subject of intense interdisciplinary research in both fundamental science and device engineering. Their size-tunable electronic and optical properties, solution processability, and diverse synthetic chemistries make them attractive candidates for applications such as photovoltaics, photocatalysis, and lighting technologies. Besides the well-known quantum confinement effect, the introduction of dopants introduces many more opportunities to tune the electronic, optical, and magnetic properties of NCs. This thesis focuses on NCs containing excess band-like electrons, their photophysical properties, and the redox chemistries associated with these dopants in relation to their charge-compensation mechanisms. Chapter 1 outlines the basic properties of degenerately doped NCs. Methods for preparing degenerately doped NCs are discussed, along with spectroscopic and electrochemical techniques for studying their optical and electronic properties. Chapter 2 describes a new method for preparing photodoped PbSe quantum dots with high electron densities. These high doping densities allow for a careful analysis of the changes in electronic absorption, which reveal conclusive evidence for the assignment of the electronic transitions in their absorption spectra. Chapter 3 employs spectroelectrochemical potentiometry to study the redox properties of excess electrons in Sn4+:In2O3 NCs. An important difference is observed between the redox properties of electrons added by photodoping compared to aliovalent doping. These differences reflect the impact of the charge-compensation motif on determining the stability of charges in degenerately doped NCs.application/pdfen-USnoneNanocrystalsPhotodopingInorganic chemistryNanoscienceChemistryThesis