Professor Delia Milliron, Univesity of Texas at Austin. "Surface Depletion in Conducting Metal Oxide Nanocrystals." Harvard/MIT Inorganic Chemistry Seminar.  Abstract:  Synthetic control over colloidal metal oxide nanocrystals has advanced so that aliovalent dopants can be introduced, producing degenerately doped semiconductors, such as indium tin oxide (ITO), with metal-like optical properties. The localized surface plasmon resonance (LSPR) absorption of these nanocrystals lies in the infrared range, while their large bandgap makes them transparent to visible light. Since the LSPR absorption can be modulated electrochemically, applications including smart windows that dynamically control solar heat gain can be envisioned. I will discuss how the depletion of electron density near the surface of the conducting nanocrystals controls the extent of modulation achievable; material parameters such as dopant concentration and nanocrystal size can be tuned to achieve desirable dynamic response. Depletion also creates a barrier to electron transport between nanocrystals in a thin film. Orders of magnitude enhancement in conductivity of transparent conductive thin films is demonstrated by tuning dopant spatial distribution and nanocrystal surface chemistry to minimize depletion.