Modeling, synthesis, and characterization of thin film copper oxide for solar cells
The modeling, growth, and characterization of Copper Oxide thin films for solar cell applications are reported. Cu_2O has several attractive properties which include its direct band gap (Eg=2.17 eV) for use in photoelectrolysis of water and use in tandem multi-junction cells. Detailed balance calculations predict efficiencies on the order of 20% while Cu_2O cells have yet to even pass 2% efficiency. The device physics model reveals that defects, particularly at the heterojunction interface, are the main reason for lowered efficiencies. Epitaxial Cu_2O (100) thin films on MgO are fabricated using RF Oxygen plasma MBE. The films are quite smooth and showed mobilites in the range of 10-100 cm^2/V*sec and carrier concentrations in the range of 10^(14)-10^(17). Finally, the epitaxial growth of Cu_2O on a MgO template is demonstrated.
Additional Information© 2009 IEEE. We acknowledge financial support from U.S. Department of Energy under grant DE-FG36-08G018006, and the Caltech Center for Sustainable Energy Research. We thank Dr. Matthew Dicken, Greg Kimball, and Carrie Hofmann for engaging discussions and assistance.