IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Processing at the Nanoscale Monday Sessions
       Session PN-MoA

Paper PN-MoA3
Interfacial Controlled, Self-assembled Copper-Oxide Nano-dots and Rings on SrTiO@sub3@(001)

Monday, October 29, 2001, 2:40 pm, Room 133

Session: Nanostructures from 0 to 3 Dimensions
Presenter: Y. Liang, Pacific Northwest National Laboratory
Authors: Y. Liang, Pacific Northwest National Laboratory
D. McCready, Pacific Northwest National Laboratory
S. Lea, Pacific Northwest National Laboratory
Correspondent: Click to Email
Since oxides exhibit a much wider range of novel electronic, optical, magnetic, and dielectric properties than semiconductors and metals, oxide nano-structures have the potential to provide systems with much higher functionality and richer behaviors. We have successfully synthesized copper oxide nano-dots and rings on SrTiO@sub3@ substrates using oxygen-plasma assisted molecular beam epitaxy. The morphological, structural, chemical, and electronic properties were examined by XPS, AFM, scanning Auger microscopy, and high-resolution XRD. Four types of nanostructures were found under different synthesis conditions: truncated dots, square pyramids, multifaceted domes, and corral-like rings. XPS measurements on band offsets show that Cu@sub2@O/SrTiO@sub3@ exhibits a type-II heterojunction with both the valance and conduction bands of Cu@sub2@O higher than that of SrTiO@sub3@, i.e quantum dot for electrons but anti-quantum dot for holes. Consequently the photo-excited electrons and holes are spatially separated with holes being confined to Cu@sub2@O quantum dots and electrons confined to SrTiO@sub3@, a property important for photocatalysis and other applications. We are currently using the surface-potential AFM and magnetic-force microscopy to elucidate the nano-scale spatial charge separation from the nanodots and the induced magnetic property from the nano-rings. @FootnoteText@ Pacific Northwest Laboratory is a multiprogram national laboratory operated by Battelle Memorial Institute for the U.S. Department of Energy under Contract DE-AC06-76RLO 1830.