Prepared And Optoelectric Properties Of Topological Triphenylamine Materials

Triphenylamine is nitrogen atom-centered with three phenyl ring planes arrangedin a propeller-like fashion structure of chromophores. The properties of propeller-likestructure can enhance the radical stability of nitrogen atom due to their larger steric andsuper conjugation electronic properties. Triphenylamine chromophores can be widelyused as photoelectric materials for their unique radical properties which makestriphenylamine unit with higher holes mobility. The three benzyl rings oftriphenylamine unit can connect different functional groups which can display uniqueactivity when they were used in optoelectronic devices in the fields of organic solarcells, electroluminescence and electrochromism. Based on the survey of thedevelopment and the state of the triphenylamine derivatives materials, thirty-twotriphenylamine derivatives are prepared, and the structures of four molecules aredetermined by single-crystal X-ray diffraction analysis. We systematically investigatedthe photoelectric properties and used the higher performance materials in photoelectricdevice. The main researching contents are as follows:1. Four novel D-A-D chromophores with hexafluorocylopentene thiophene "core"flanked on topological triphenylamine unit were synthesized and their organicphotovoltaic (OPV) properties were investigated. The topological triphenylamine groupcan accelerate the open-ring isomer of hexafluorocylopentene thiophene to be closed,which has contribution to intramolecular π-conjugation extension and resultinglybroaden to absorption spectra widening, ranging from200nm to850nm with highoptical densities. The chromophores in this dissertation show obvious dualsemiconductor properties (n-and p-type) owing to the fluorine atom substitution on thecenter of hexafluorocylopentene and the better hole-transport characteristics oftopological triphenylamine moiety on the molecular periphery. Devices1is promisingorganic solar cell materials when fabricated in device showing0.22%power-conversionefficiency (). 2. Three pyrenyltriphenylamine chromophores have been designed, synthesizedand applied in organic light-emitting devices (OLED). One molecule is determined bysingle-crystal X-ray diffraction analysis. The results of thermal stability andphotoelectric characteristics show the triphenylamine-pyrene chromophores with higherthermal stability and higher fluorescence quantum yield. Chromophores as a blueemitter in a typical three layers OLED exhibit blue electroluminescence peak at456nm(CIE x=0.17, y=0.20) for chromohore I and472nm (CIE x=0.16, y=0.30) forchromophore II. Using chromophore II as an emitter in a four layers OLED, efficientblue emission with the maximum brightness4200cd/m~2and the maximumluminescence efficiency of5.14cd/A (1.88lm/W) are obtained.3. A new class of topological triphenylamine derivatives based on terpyridylmoieties was synthesized and their photoelectric properties were investigated in detail.At the same time, the chromophores4and7were used as emitter in OLED, and theirelectroluminescent characteristics were investigated. The results show that theabsorption peaks of multibranches terpyridyl chromophores (chromophores2,3,5,6,8,9) are redshifted with the largest red-shift of18nm, comparision with those ofmonobranch chromophores (chromophore1,4,7), respectively. The UV-vis absorptionintensity of multibranches terpyridyl chromophores is larger than those of monobranchchromophores in solid state. All chromophores show stronger fluorescence emissionproperties. With the increasing number of terpyridyl "branches", the fluorescencelifetime of the chromophores growth, but the fluorescence quantum yield with adownward trend. The monobranch chromophores1,4,7show obvious electrochemicalredox peaks. The oxidation peaks of chromophores1-3are significantly higher than theother series of chromophores. In addition, the oxidation peaks gradually increase toreach0.5V with the increasing terpyridyl "branches". All chromophores with goodthermal stability, their thermal decomposition temperatures are higher than300oC. Twochromophores with rigid benzyl unit or flexibly styryl unit, named chromophore4,chromophore7, have been used in OLED as emitter. The result shows that theluminescent properties of four layers devices better than that of three layers device andthe added TAPC hole-transporter can effective enhance the luminous intensity. Theoptimized device structure of NPB/TAPC/chrom4/BCP/LiF exhibit blue EL peak at460nm (CIE x=0.17, y=0.20) with the maximum brightness3000cd/m~2.4. Based on the synthesis of topological triphenylamine-terpyridine chromophores, we prepared sixteen triphenylamine-terpyridyl metal complexes. Their UV-visabsorption, fluorescence emission, electrochemical and electrochromic properties wereinvestigated in solution and polymer solid films. The results show that the ligands andmetal ions effect on the electrochromic stability, fatigue resistance. The absorptionpeaks range of491-520nm/571-578nm are contributed to the formationML(metal-to-ligand) electronic transition of metal Ru(II)/Fe(II) and the ligands. Withdifferent ligands, the ML electronic transition absorption peaks are different in the rangeof27nm, but there only3nm deviations in the polymerization metal complexes. AllRu(II) complexes cannot show electrochromic properties under the voltage of0.0-10.0V in dichloromethane, but the Fe(II) complexes exhibit different electrochromicproperties affected by their ligands. Among the Fe(II) complexes, one of the MLabsorption intensity can drop about70%from0.0V to10.0V. The polymerizationmetal complexes can show reversible changes the ML absorption intensity in the rangeof0.0-2.0V, along with the increase of voltage, the intensity of ML absorption peaksgradually reduced to disappear, and as the voltage decreased, the intensity of MLabsorption peaks return to its original state. This metal (II) combined with differentpolymerization ligands show different colors under different voltages. In the range of0.0-2.0V, the polymer1-Ru/Fe, polymer4-Ru/Fe, polymer7-Ru/Fe can reversiblechanges between orange red and blue, dark violet and green yellow, orange red and lightgreen, dark violet and dark green, orange red and dark green, purple and dark blue,respectively.