AVS 52nd International Symposium
    Surface Science Wednesday Sessions
       Session SS+EM-WeA

Paper SS+EM-WeA1
Comparison of the Electronic Structure of Ferroelectric Polymers

Wednesday, November 2, 2005, 2:00 pm, Room 202

Session: Organic Film Growth and Characterization
Presenter: J. Xiao, University of Nebraska-Lincoln
Authors: J. Xiao, University of Nebraska-Lincoln
L.G. Rosa, University of Nebraska-Lincoln
M. Poulsen, University of Nebraska-Lincoln
D.Q. Feng, University of Nebraska-Lincoln
S. Ducharme, University of Nebraska-Lincoln
P.A. Dowben, University of Nebraska-Lincoln
Correspondent: Click to Email
We compare the electronic structure of copolymers of polyvinylidene fluoride with trifluroethylene P(VDF-TrFE, 70%:30%) with polymethylvinylidenecyanide (PMVC). Crystalline thin films can be formed from both ferroelectric polymers and we find that in both cases the dipole is aligned along the surface normal. The P(VDF-TrFE) copolymer is generally observed to have the chemical potential close to the lowest unoccupied molecular orbital,@footnote 1@ with a band gap of about 6 eV.@footnote 2@ PMVC exhibits a much greater band gap, with the Fermi level placed roughly mid way within the highest occupied to lowest unoccupied molecular orbital (HOMO-LUMO) gap. The implications of these differences in electronic properties will be discussed, in particular with regard to electron-phonon coupling.@footnote 3@ @FootnoteText@ @footnote 1@Jaewu Choi, P.A. Dowben, S. Pebley, A. Bune, S. Ducharme, V.M. Fridkin, S.P. Palto, N. Petukhova, Phys. Rev. Lett. 80 (1998) 1328-1331@footnote 2@Chun-gang Duan, W.N. Mei, J.R. Hardy, S. Ducharme, J. Choi, P.A. Dowben, Europhys. Lett. 61 (2003) 81-87@footnote 3@Luis G. Rosa, Ya.B. Losovyj, J. Choi, and P.A. Dowben, J. Physical Chemistry B 109 (2005) 7817-7820.