Electric Field Effect on Photoinduced Electron Transfer Processes in Photoconductive Aromatic Vinyl Polymer Films
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Kyoto Institute of Technology|
AKIRA Itaya Kyoto Institute of Technology, Department of Polymer Science and Engineering, Professor, 繊維学部, 教授 (80035071)
|Project Period (FY)
1998 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1999 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1998 : ¥2,500,000 (Direct Cost : ¥2,500,000)
|Keywords||Photoconductivity / Fullerene / Photoinduced Electron Transfer / Hole Migration / Carbazole / Amorphous Solid / Charge Recombination / Electric Field Effect / カルバソール|
1. Electric field effects were investigated for transient absorption in poly(N-vinylcarbazole)(PVCz) films doped with 1,2,4,5-tetracyanobenzene (TCNB). The electric fields resulted in a decrease in the recombination rate of photoinduced-charge carriers in the microsecond time region. The result rejected the early-proposed mechanism for the photoinduced charge generation, and proposed the mechanism including sequential hole migration processes.
2. Primary processes of photoinduced electron transfer in a PVCz-TCBN film were investigated in the temperature range between 77 and 295 K.No temperature dependence was observed for the rate constant of the hole shift reaction in the initial stages after photoexcitation, while weak temperature effect was obtained for the charge recombination. The mechanisms regulating efficient hole migration were discussed.
3. Dynamics of formation and deactivation processes was discussed for extremely long-lived charge-separated states following photoinduced elec
tron transfer in carbazolyl polymers coadsorbed with TCNB on a macroreticular resin at room temperature.
4. The absorption spectra of singlet and triplet excited states of C_<60> in twelve solvents did not correlate with either dielectric constant of the solvents or their refractive index, but with their ionization potential. These solvent-dependent absorption spectra were ascribed to C_<60>-excited states with a distortion induced by specific interactions with solvent molecules through the donation of their π-electron density without forming obviously excited-state complexes.
5. Photoinduced electron transfer processes between carbazolyl (Cz) dimer compounds and C_<60> in benzonitrile were investigated. By excitation of C_<60>, electron transfer occurred via the triplet excited state of C_<60>. Excitation of the Cz-dimer compounds produced the Cz radical cations and solvated electron. After that, the latter was trapped with C_<60>.
6. Photoirradiation on benzonitrile solution of PVCz and C_<60> gave colored polymer. Enhanced steady-state photocurrent of the colored polymer films was obtained for the visible light region. Less
Research Output (9results)