Principal Investigator Harry Tuller
Efficient transparent electrode materials are vital for applications in smart window, LED display, and solar cell technologies. These materials must possess a wide band gap for minimal optical absorption in the visible spectrum while maintaining a high electrical conductivity. Tin-doped indium oxide (ITO) has been the industry standard for transparent electrodes, but the use of the rare element indium has led to a search for better material alternatives. BaSnO3 represents a promising alternative due to its high electron mobility and resis- tance to property degradation under oxidizing condi- tions, but the mechanisms by which processing con- ditions and defect chemistry affect the final material properties are not well understood.
This work seeks to better understand the relationships between processing, defect chemistry, and material properties of BaSnO3, in order to better establish the consistent and controllable use of BaSnO3 as a transparent electrode. To accomplish these goals, methods such as in-situ resistance and impedance monitoring during annealing will be applied. In addition, a variety of novel methods such as the in situ monitoring of optical transmission during annealing and the in-situ monitoring of resistance during physical vapor deposition will be utilized to investigate BaSnO3. Direct measurements of the key constants for the thermodynamics and kinetics of oxidation in donor-doped BaSnO3 will be experimentally determined for the first time. This increase in understanding will provide a predictive model for determining optical properties, carrier concentrations, and electron mobilities in BaSnO3, which may be become increasingly important due to its high electron mobility, high temperature stability, and favorable crystal structure.