LI Mao, LU Ping, ZHANG Hai-quan, LU Dan, MA Yu-guang. Electrochemical Determination of the Ionization Potential and Electron Affinity of PF Derivatives[J]. Chinese Journal of Luminescence, 2006,27(1): 80-84
LI Mao, LU Ping, ZHANG Hai-quan, LU Dan, MA Yu-guang. Electrochemical Determination of the Ionization Potential and Electron Affinity of PF Derivatives[J]. Chinese Journal of Luminescence, 2006,27(1): 80-84DOI:
Electrochemical Determination of the Ionization Potential and Electron Affinity of PF Derivatives
Cyclic voltammetry measurements for the blue-emitting conjugated PF and its derivatives were reported.Both oxidation and reduction potentials onsets were determined and thus the ionization potentials
I
p
and electron affinities
E
a
of the polymers under the same experimental condition were estimated. The oxidative potential onset of PF was at 0.97 V and the reductive potential onset at-2.58 V. In order to increase the electron-accepting ability
the bipyridine units were introduced to the polymer backbone (PP). PP3(with 50% bipyridine content) displayed greater potential change in the reductive potential (-0.37 V) compared with PF because the bipyridine in PP3 is an electron-deficient. PP3 showed a good electro-accepted ability. The
E
a
was increased from the 2.05 eV to 1.92 eV compared with that of PF. In the anodic scan
the onsets of oxidation of PS
PO
PC and PD was at 1.10
1.11
1.10 and 1.06 V which correspond to the ionization potential (
I
p
) values of 5.73
5.74
5.73 and 5.69 eV.The electron affi-nity (
E
a
) values of the polymers were determined to be 2.16
2.08
1.92 and 1.96 eV. The incorporation of the seven-membered ring moiety into the polymer backbone led to wider bandgaps. It indicates that the seven-membered ring compound was an efficient segment for tailoring the band gap of the conjugated polymer. The shift of redox potential
change of the ionization potential and electron affinity were due to the different seven-membered ring structures. The band gap of the PF derivatives was increased by introducing the seven-membered ring
especially for the meta-linkage polymers. The electrochemical energy gap agrees well with the optical energy for these copolymers.
关键词
Keywords
references
Lu Ping,Zhang Haiquan,Shen Fangzhong,et al.A wide-bandgap semiconducting polymer for ultraviolet and blue light emitting diodes[J].Macromol.Chem.Phys.,2003,204:2274-2280.
Zhang H Q,Yang B,Zheng Y,et al.New biphenyl derivative with planer phenyl-phenyl conformation in crystal at room temperature exhibits highly efficient UV light-emitting[J].J.Phys.Chem.B,108:9571-9573.
Inbasekaran M,Woo E,Wu W,et al.Fluorene homopolymers and copolymers[J].Synth.Met.,2002,111-112:397-401.
Chen Zhizhong,Li Fushan,Gong Qihuang.Novel blue organic light-emitting diodes and materials[J].Chin.J.Lumin.(发光学报),2005,26(6):743-747 (in Chinese).
Osaheni J A,Jenekhe S A,Perlstein J.Photogeneration of charge carriers in bilayer assemblies of conjugated rigid-rod polymers[J].J.Phys.Chem.,1994,98:12727-12736.
Shirota Y,Kuwabara Y,Inada H.Multilayered organic electroluminescent device using a novel starburst molecule,4,4',4-tris(3-methylphenylphenylamino)triphenylamine,as a hole transport material[J].Appl.Phys.Lett.,1994,65:807-809.
Alvarado S F,Libioulle L,Seidler P F.STM-excited luminescence on organic materials[J].Synth.Met.,1997,91:69-72.
Kim Joo-Hyun,Lee Hoo-Sung.Improvement of efficiency of the single-layer polymerlight-emitting diodes:the exciton confinement in the emitting layer by conjugated 1,3,4-oxadiazole[J].Synth.Met.,2004,114:169-176.
Bredas J L,Silbey R,Boudreaux D S,et al.Chain-length dependence of electronic and electrochemical properties of conjugated systems:polyacetylene,polyphenylene,polythiophene,and polypyrrole[J].J.Am.Chem.Soc.,1983,105:6555-6559.
Leeuw D M de,Simenon M M J,Brown A R,et al.Stability of n-type doped conducting polymers and consequences for polymeric microelectronic devices[J].Synth.Met.,1997,87:53-59.
Cervini R,Li X C,Spencer G W C,et al.Electrochemical and optical studies of PPV derivatives and poly(aromatic oxadiazoles)[J].Synth.Met.,1997,84:359-360.
Ding Bangdong,Zhang Jimei,Zhu Wenqing,et al.Convenient electrochemical method to determine the energy level of organic electroluminescent materials[J].Chin.J.Lumin.(发光学报),2003,24(6):606-611 (in Chinese).
Lu Hong-Fang,Chan Hardy S O,Ng Siu-Choon.Synthesis,characterization,and electronic and optical properties of donor-acceptor conjugated polymers based on alternating bis(3-alkylthiophene) and pyridine moieties[J].Macromolecules,2003,36:1543-1552.
Ding Jianfu,Tao Ye,Day M,et al.Electrochemical and fluorescent properties of alternating copolymers of 9,9-dioctyl-fluorene and oxadiazole as blue electroluminescent and electron transport materials[J].J.Opt.A:Pure Appl.Opt.4,2002,4:S267-S272.
Kreyenschmidt M,Uckert F,Mullen K A.New soluble poly(p-phenylene) with tetrahydropyrene repeating units[J].Macromolecules,1995,28:4577-4582.
Anderson J D,McDonald E M,Lee P A,et al.Electrochemistry and electrogenerated chemiluminescence processes of the components of aluminum quinolate/triarylamine,and related organic light-emitting diodes[J].J.Am.Chem.Soc.,1998,120:9646-9655.
Janietz S,Bradley D D C,Grell M,et al.Electrochemical determination of the ionization potential and electron affinity of poly(9,9-dioctylfluorene)[J].Appl.Phys.Lett.,1998,73:2453-2455.
Chen Z K,Huang W,Wang L H,et al.A family of electroluminescent silyl-Substituted poly(p-phenylenevinylene)s:synthesis,characterization,and structure-property relationships[J].Macromolecules,2000,33:9015-9025.
Low Threshold Polymer Lasers Under Optical Pumping
White Light-emitting Electrochemical Cells Based on Polyfluorene and Cationic Iridium Complexes
Synthesis, Spectral and Electrochemical Properties of A New Tailed Porphyrin
Materials and Devices in the Field of Polyfluorene Derivatives Organic Electroluminescence
Energy-band Structures of Organic Light-emitting Materials by STM and Cyclic Voltammetry
Related Author
QU Song-nan
LIU Xing-yuan
LIN Jie
GUO Tai-liang
ZENG Qun-ying
NIE Chen
LI Fu-shan
WU Jia-qi
Related Institution
State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
University of Chinese Academy of Sciences, Beijing 100049, China
Institute of Optoelectronic Display, College of Physics and Information Engineering, Fuzhou University
School of Science, Beijing Jiaotong University
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences