Comparison of the theoretical and experimental band structure of poly(vinylidene fluoride) crystal
Department of Physics, University of Nebraska at Omaha Omaha,
NE 68182-0266, USA
2 Department of Physics and Center for Materials Research and Analysis University of Nebraska at Lincoln - Lincoln, NE 68588, USA
Corresponding author: email@example.com.
Accepted: 7 October 2002
The electronic structure and band symmetries of the ferroelectric phase of poly (vinylidene fluoride) (PVDF) are studied by using the first-principles density-functional method. Our calculated results agree well with the angle-resolved photoemission experiments. We find that the PVDF crystal has an energy gap of about 6 at the Γ-point. Large dispersion of the valence band is found only along the chain direction, which is consistent with the quasi–one-dimensional nature of PVDF. In particular, the band symmetries of the valence states deduced theoretically are in good agreement with experiment. Finally, further investigations on the electronic structure of poly(trifluoroethylene) (PTrFE) reveal that the replacement of -(-)- by -(-)- does not change major features of the band structure.
PACS: 71.20.Rv – Polymers and organic compounds / 71.20.-b – Electron density of states and band structure of crystalline solids / 71.15.Ap – Basis sets (plane-wave, APS, LCAO, etc.) and related methodology (scattering methods, ASA, linearized methods)
© EDP Sciences, 2003