Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (2): 281-288.doi: 10.3866/PKU.WHXB201312171

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Electronic Structures and Optical Properties of Poly(vinylidene fluoride) Crystals

CHENG He-Ping1,2, CHEN Guang-Hua1, QIN Rui1, DAN Jia-Kun1, HUANG Zhi-Meng1, PENG Hui3, CHEN Tu-Nan1,4, LEI Jiang-Bo1   

  1. 1 Institute of Fluid Physics, China Academy of Engineering Physics, Miangyang 621900, Sichuan Province, P. R. China;
    2 Institute of Applied Physics, School of Mechatronics and Information Engineering, Huangshan University, Huangshan 245041, Anhui Province, P. R. China;
    3 State Key Laboratory of Explosion and Technology, Beijing Institute of Technology, Beijing 100081, P. R. China;
    4 Institute of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, P. R. China
  • Received:2013-09-11 Revised:2013-12-17 Published:2014-01-23
  • Contact: CHENG He-Ping, CHEN Tu-Nan E-mail:tunxi72@126.com;ctn_666@sina.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (11272298, 11204281), Joint Foundation of the National Natural Science Foundation of China and the China Academy of Engineering Physics (U1230128), and Science and Technology Development Foundation of CAEP, China (2013B0102003).

Abstract:

The electronic structures and optical properties of the nine poly(vinyldene fluoride) (PVDF) crystalline forms are calculated by the first-principles method based on density functional theory with inclusion of the Tkatchenko-Scheffler (TS) dispersion corrections. The nine crystalline forms of PVDF are insulators with band gap energies from6.05-7.34 eVat zero pressure and zero temperature. The calculated results of the band gap energy of the Ⅰp (β) and Ⅱad crystalline forms are close to other experimental data or calculated results. The energy bands of PVDF crystals are dense and straight. The valence bands consist mainly of F-2s and F-2p states and the conduction bands are dominated by C-2p and H-1s states. In the 0-35 eV photon energy range, the optical properties, such as dielectric function, absorption, reflectivity and refractive index, primarily change in the deep ultraviolet region in our calculations. According to the spectra features (spectral range, peaks, etc.) of the optical properties, the nine crystalline forms of PVDF can be divided into four categories: {Ⅰp}, {Ⅱpu}, {Ⅱau, Ⅱad, Ⅱpd, Ⅲpu}, {Ⅲau, Ⅲad, Ⅲpd}. The crystalline forms in each category have similar spectra features.

Key words: Poly(vinyldene fluoride), Electronic structure, Optical property, First-principles