MTL Annual Research Report 2013

Utilization of Doped-ZnO and Related Materials Systems for Transparent Conducting Electrodes

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.  Currently, tin-doped indium oxide (ITO) is the industry standard for transparent electrodes, but limitations in both deposition temperature and use of the rare element indium has led to a search for better material alternatives.  Doped ZnO represents one of the most promising alternatives, but the mechanisms by which processing conditions and defect chemistry affect the final material properties are not well understood.  Reported values of the electrical conductivity for doped ZnO span orders of magnitude for seemingly similar processing conditions performed by different experimental groups.  This work seeks to better understand the relationships between processing, defect chemistry, and material properties through in situ and ex situ optical and electrical investigation of doped ZnO, deposited by pulsed laser deposition and magnetron sputtering methods.