Effect of Thin Polymer Layers on the Performance of ZnO/Cu$_2$O Solar Cells

Transition metal oxides are a class of stable, non-toxic, and inexpensive semiconductors with great potential in low-cost photovoltaics (PV) applications. Cu$_2$O is a versatile p-type oxide that absorbs visible light and can be solution-processed at low temperatures. ZnO is a wide-E$_g$ n-type material with good electronic properties and has already been widely incorporated into other low-cost PV technologies such as organic and dye-sensitized solar cells. While ZnO/Cu$_2$O devices have large theoretical efficiencies (as high as 20\%) [1], practical devices do not reach their full potential due to poor charge collection and recombination. ZnO/Cu$_2$O PV's can be improved by optimizing deposition conditions, such as solution pH and temperature, and device geometry, such as layer thickness [2]. This talk, however, will discuss how semiconducting polymer layers can further enhance performance for scalable device fabrication. In particular, polymer type and the Cu$_2$O/polymer interface will be discussed as routes to better performance. \\[4pt] [1] J. Nelson. \emph{The Physics of Solar Cells}. Imperial College Press, 2003 \newline [2] Musselman et al., unpublished