AVS 49th International Symposium
    Photonic Materials Topical Conference Thursday Sessions
       Session PH-ThM

Paper PH-ThM7
Resonant Photoemission of the TiO@sub 2@/CuI Interface: Towards New Solid State Photovoltaic Cells

Thursday, November 7, 2002, 10:20 am, Room C-111B

Session: Photonic Nanostructures
Presenter: A.G. Thomas, UMIST, UK
Authors: W.R. Flavell, UMIST, UK
A.G. Thomas, UMIST, UK
A.R. Kumarasinghe, UMIST, UK
A.K. Mallick, UMIST, UK
D. Tsoutsou, UMIST, UK
G.C. Smith, UMIST, UK
R.L. Stockbauer, Louisiana State University
M. Grätzel, Swiss Federal Institute of Technology
R. Hengerer, Swiss Federal Institute of Technology
Correspondent: Click to Email
Currently, nanocrystalline metal oxide semiconductor films, notably anatase TiO@sub 2@, are the subject of intense discussion because of their potential application in a number of charge-separating devices such as dye sensitised liquid state and solid sta te solar photovoltaics, which are considered to be possible alternatives for Si based solar cells. In a recently proposed solid state device, p-type CuI is deposited onto n-type 'dye-sensitised' TiO@sub 2@ in order to form the pn junction central to the o peration of the cell.@footnote 1,2@ In this work, resonant photoemission at the Daresbury SRS is used to investigate the electronic structure of the prototype junction formed by depositing CuI from a getter source onto both rutile and anatase single cryst al surfaces. Valence band resonant photoemission spectra at the Cu 3p-3d and Ti 3p-3d edges are monitored for a number of coverages and compared with data recorded for single crystal TiO@sub 2@ (rutile and anatase) and polycrystalline CuI. At the Cu 3 p t hreshold, a very strong and prolonged resonance is observed, consistent with earlier observations from the copper halides@footnote 3@. Shifts in the resonance energies between the 'junction' and its component layers are interpreted in terms of Cu-3d/Ti-3d hybridisation at the interface. @FootnoteText@ @footnote 1@ K. Tennakone, G.R.R.A. Kumara, A.R. Kumarasinghe, K.G.U. Wijayantha, and P.M. Sirimanne, Semicond Sci Technol, 10, (1995), 1689.@footnote 2@ U. Bach, D. Lupo, P. Comte, J.E. Moser, F. Weissörtel, J. Salbeck, H. Spreitzert, and M. Grätzel, Nature, 395, (1998), 544@footnote 3@ T. Ishii, M. Taniguchi, A. Kakizaki, K. Naito, H. Sugawara, and I. Nagakura, Phys Rev B, 33, (1986), 5664. 1.