TY - GEN
T1 - Band gap energies and localized states in several insulating polymers estimated by optical measurements
AU - Ohki, Yoshimichi
AU - Fuse, Norikazu
AU - Arai, Tomoyuki
PY - 2010/12/1
Y1 - 2010/12/1
N2 - The band gap energy was estimated experimentally by measuring the change in optical absorption intensity as a function of photon energy in a wide range from visible to vacuum-ultraviolet wavelengths for commercially available 11 kinds of insulating polymers. The absorption spectra as a function of photon energy measured by synchrotron radiation and by a spectrometer agree with each other at the photon energies where the two measurements were available. The band gap energy is quite high in linear polyolefin polymers. Namely, it is 6.9 and 7.0 eV for polyethylene and polypropylene, respectively. In these two polymers, the relative permittivity at 1 kHz is quite low in both polymers. On the other hand, the polymers with aromatic rings in their structures have low band gap energies and large permittivities. Namely, a negative relationship between the band gap energy and permittivity, which is well known for inorganic solids, is also seen in insulating polymers. Furthermore, to investigate the possibility of appearance of midgap localized states by the addition of nanofillers, absorption and luminescence spectra were examined for polymer nanocomposites based on polyethylene and polyamide. As a result, the nanofiller addition was found to give no influences on their band gaps.
AB - The band gap energy was estimated experimentally by measuring the change in optical absorption intensity as a function of photon energy in a wide range from visible to vacuum-ultraviolet wavelengths for commercially available 11 kinds of insulating polymers. The absorption spectra as a function of photon energy measured by synchrotron radiation and by a spectrometer agree with each other at the photon energies where the two measurements were available. The band gap energy is quite high in linear polyolefin polymers. Namely, it is 6.9 and 7.0 eV for polyethylene and polypropylene, respectively. In these two polymers, the relative permittivity at 1 kHz is quite low in both polymers. On the other hand, the polymers with aromatic rings in their structures have low band gap energies and large permittivities. Namely, a negative relationship between the band gap energy and permittivity, which is well known for inorganic solids, is also seen in insulating polymers. Furthermore, to investigate the possibility of appearance of midgap localized states by the addition of nanofillers, absorption and luminescence spectra were examined for polymer nanocomposites based on polyethylene and polyamide. As a result, the nanofiller addition was found to give no influences on their band gaps.
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U2 - 10.1109/CEIDP.2010.5723991
DO - 10.1109/CEIDP.2010.5723991
M3 - Conference contribution
AN - SCOPUS:79952911764
SN - 9781424494705
T3 - Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP
BT - 2010 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2010
T2 - 2010 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2010
Y2 - 17 October 2010 through 20 October 2010
ER -