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A new iridium complex was synthesized and demonstrated a saturated red light emission in organic light-emitting diodes (OLEDs). The maximum brightness of 2800 cd/m 2 and the external quantum efficiency of 5.5% were achieved in multilayer OLEDs. The peak wavelength of the emission was found to be at 677 nm with the Commission Internationale de l’Eclairage (CIE) coordinates of (0.71, 0.27).

A series of polyfluorene derivatives endcapped by 0.1–2 mol% 1,8-naphthalimide dye were synthesized by Yamamoto coupling reaction. The resulting polymers show the promising electroluminescence (EL) performance with emission predominantly from the 1,8-naphthalimide unit due to energy transfer and charge trapping from polyfluorene backbone to 1,8-naphthalimide dye. Single-layer devices were fabricated with a device configuration of ITO/PEDOT/polymer/Ca/Al. Among all the devices tested, the device of NFP50 exhibited the current efficiency of 7.40 cd/A, the power efficiency of 2.89 lm/W and the maximum brightness of 19280 cd/m 2 , about 30 times more efficient than that of polyfluorene without endcapping groups.

Two polyfluorenes containing 1,8-Naphthalimide units were synthesized by Yamamoto polycondensation reaction. The 1,8-naphthalimide moieties act as both electron and hole trap in the resulting polymers, leading to the EL spectra different from the PL spectra in film. White electroluminescence with a maximum brightness of 11100 cd/m2, an external quantum efficiency of 2.0% and CIE coordinates of (0.26, 0.36) has been realized through partial energy transfer from polyfluorene to 1,8-naphthalimide moieties.

A novel series of emitting aluminum complexes containing two 8-hydroxyquinoline ligands (q) and a phenolato ligand (p) were synthesized and characterized. Double layer organic light-emitting diodes (OLEDs) were fabricated using these complexes as luminescent layers, and strong electroluminescence (EL) was observed. It was found that their emitting wavelengths were mainly determined by the first ligands (q). Cyclic voltammograms revealed a partially irreversible n-doping process and indicated that these complexes show excellent electron-transporting ability.

Polyaniline (PANI), a member of the intrinsically conducting polymer (ICPs) family, was blended with polyamide-11 (polyco-aminoundecanoyle) in concentrated sulfuric acid. The above solution was used to spin conductive PANI/polyamide-11 fibers by wet-spinning technology. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to study the two-phase morphology of the conductive PANI/polyamide-11 fibers. The micrographs of the cross-section, the axial section and the surface of the monofilament demonstrated that the two blend components were incompatible. The morphology of PANI in the fibers was of fibrillar form, which was valuable for producing conducting channels. The electrical conductivity of the fibers was from 10(-6) to 10(-1) S/cm with the different PANI fraction and the percolation threshold was about 5 wt.%. By comparing the two blend systems of PANI/Polyamide-11 fibers and carbon black filled poly(ethylene terephthalate) (PET) fibers, it was shown that the morphology of the conductive component had an influence on electrical conductivity, The former had higher conductivity and lower percolation threshold than the latter. (C) 2001 Elsevier Science B.V. All rights reserved.

Polyaniline (PAn) with different molecular weight was prepared by adding organic solvents such as acetone, ethanol or THF into the polymerization mixture. Open-circuit potential measurements showed that the polymerization rate was lowered by the addition of the organic solvent. Spectral studies showed that PAn intermediate before the oxidant was consumed was pernigraniline and it was reduced to emeraldine base rapidly by aniline in the termination period. A mechanism of chain propagation was proposed. Chain propagation and autoacceleration period were almost independent of addition of pernigraniline, and the autoacceleration of aniline polymerization is due to more rapid initiation rate.

Solutions of polyaniline (PAn), poly (ortho-toluidine) (POT) and poly (ortho-anisidine) (PAs) in N-methyl pyrrolidinonne (NMP) were examined by viscometric, gel permeation chromatographic (GPC) and rheological methods. Strong intermolecualr interaction and molecular aggregation are shown.

The electrical conductivities of pernigraniline after ion implantation with potassium ions were studied experimentally. Pernigraniline films were irradiated with doses ranging from 1 × 10 13 to 1 × 10 17 K + ions/cm 2 at 40 keV. The electrical conductivity was observed to increase over about eight orders of magnitude. The temperature dependence of the conductivity of the ion-bombarded layer could be fitted with the eqaation, σ = σ 0 exp[ −( T 0 / T ) 1/2 ]. It is of interest to note that the film exhibits n-type semiconducting properties in the implanted layer. Rutherford backscattering (RBS) and elastic recoil detection (ERD) measurements and analysis in the characterization of depth profiles of nitrogen and hydrogen are presented. Infrared spectra reveal a decrease in the nitrogen quinone group (N=Q=N) stretching vibration at 1583 cm −1 and an increase in the nitrogen benzene group (N-B-N) stretching vibrations at 1485 cm −1 , which are interpreted in terms of then n-doping of the pernigraniline form (simultaneously accompanied with chemically reducing process in the fully oxidized state of polyaniline).

A surface emitting microcavity was formed by sandwiching a polymer film containing PVK, Alq(3) and DCM between a distributed Bragg reflector (DBR) with a reflectivity of 99% and a silver film (300 nm). The lasing phenomenon was observed in DCM-doped PVK microcavity. The full width at half maximum (FWHM) was 0.6 nm with the peak wavelength at 603 nm. The threshold energy for lasing was estimated to be about 2.5 mu J per pulse. (C) 2000 Published by Elsevier Science S.A. All rights reserved.

The reactions of polyaniline and poly-omicron-methylaniline of different oxidation degrees with I2 were followed by FTIR and electrical conductivity measurements. The results showed that the reaction of common polyanilines with I2 was oxidation in nature whereas that of the fully reduced ones was doping. The latter took place in two steps: oxidation of benzene-diamine units into quinone-diimine units (redox between I2 and the polymer chain) and formation of a conjugated system consisting of four aromatic rings (intramolecular chain redox).

The chemical polymerization of ortho-methylaniline (MAn) is performed in aqueous solution of six protonic acids. The MAn polymerization conversion, and the electrical conductivity and doping level as well as molecular chain structure of the polymers obtained depend not only on the acid concentration but also on their acidity and molecular size.

A novel doping phenomenon of fully reduced polyaniline and poly-o-methylaniline, “light-assisted oxidative doping”, was found for the forst time. The doping reaction was followed by FTIR, UV-VIS, ESR and electrical conductivity measurements. It was shown that the fully reduced polyanilines in the form of HCl-salts undergo a spontaneous transition from an insulator or semiconductor to a conductor when exposed to air and light, and their final molecular chain structures are analogous to those found in HCl-doped common polyanilines.

With a newly synthesized poly(p-phenylene vinylene) (PPV) multiblock copolymer used in a triple-layer structure, efficient green light-emitting diodes with low driving voltage have been fabricated. The devices are turned on at 2.5 V, the brightness at 5 V is above 100 cd/m(2) and at 7 V is about 1650 cd/m(2), with an external quantum efficiency of about 1%. (C) 1998 Elsevier Science S.A. All rights reserved.

A novel thermally stable terbium carboxylate complex, Tb(MTP),(phen) (MTP=monotetradecyl phthalate, phen=1,10-phehanthroline). was synthesized and characterized. The device structure of glass substrate/indium-tin-oxide/poly(p-phenylenevinylene) (PPV)/poly (N-vinycarbazole) (PVK):Tb(MTP),(phen): 1,3,4-oxadizole derivative (PBD)/tris(8-hydroxyquinoline) (AIq 3 )/aluminum (Al) was employed to study the electroluminescent properties of Tb(MTP),(phen). A green emission with extremely sharp spectral band of less than 10 nm at 544 nm peak wavelength was observed. A maximum luminance of 152 cd/m 2 and an external quantum efficiency of 0.017% were achieved at a drive voltage of 24 V. A possible mechanism of energy transfer based on the polymer doped with lanthanide organic complex was also proposed.

The PL and EL properties of the polymer blends of PVK and blue PPV copolymer were studied. Considerable enhancement of both the photoluminescent and the electroluminescent intensity were observed by using the polymer blends as emission layer in the LED devices. The energy transfer process and the formation of exciplex in the polymer blends were also discussed.

A series of novel PPV derivative copolymers with good solubility in common organic solvents were synthesized. The emitting color of these copolymers could range from red to blue by adjusting the structures and the compositions of monomers. Investigation on their optical properties showed that the PL quantum efficiency could be increased by energy transfer and conjugation reduction. The PL quantum efficiency of most green/blue copolymer films on slide glass was higher than 80%.

Bright blue electroluminescent devices have been fabricated using poly( N -vinylcarbazole) (PVK) doped with perylene as the emissive layer, poly( p -phenylenevinylene) (PPV) as the hole-transporting layer, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), tris(8-hydroxyquinoline) aluminum (Alq 3 ) as the electron-transporting layer, and Al as the cathode. A luminance of 700 cd/m 2 and a luminescent efficiency of 0.8% are achieved at a drive voltage of 36 V. In the experiment, it is found that the introduction of electron-transporting layer PBD has a great effect on the emissive color of the electroluminescent devices prepared by PVK doped with perylene. Yellow-green emission is observed from the device structure of glass substrate/indium-tin-oxide/PVK:perylene/Al. The possible emissive mechanisms are given. The effect of the transporting layer on the electroluminescence is also discussed.

A soluble polymer emitting green color with high efficiency was synthesized. Bright green electroluminescence devices, both single layer and multilayer, were fabricated. The luminous efficiency was improved dramatically. Carrier injection from the electrodes to the emissive layer and concomitant green electroluminescence from the emissive layer were observed. A luminance of 920 cd/m(2) and luminous efficiency of 5.35 1m/W were achieved at a drive voltage of 15 V for the multilayer device. (C) 1997 Elsevier Science S.A.

Polyaniline was doped with sulfonated PS, PPO and PEEK. The properties of doped polyaniline depended on the processing method and the structure of main chain backbone of the macromolecular acid.

Oxidative polymerization of aniline in the presence of H2O2/Fe2+/HCl was carried out, and polyaniline obtained showed similar molecular structure compared to that prepared in (NH4)2S2O8 system.

Soluble poly (o-toluidine) (POT), poly(o-anisidine) (PAs) and poly (o-chloroaniline) (PCAn) were doped with camphorsulfonic acid (CSA). The conductivity and UV-Vis spectra of the CSA-doped POT, PAs and PCAn were studied. These properties were found to be dependent on the solvent used. The cast films from m-cresol solution exhibit more effective doping and higher conductivity.

The interaction of N-methyl-2-pyrrolidone (NMP) and organic acid doped polyaniline (PAn) is studied by UV-Vis-NIR spectroscopy. A dedoping effect is observed when the doped PAn solution is extremely diluted by NMP. This effect is due to a strong interaction between NMP and the dopant acid. The competition between NMP and PAn is responsible for the poor conformation of doped polyaniline in NMP solution and the poor conductivity of the film cast from this solution.

The present paper reports the synthesis of glycidyl monoether of 4-[(p-nitrophenyl) azo] phenol (GMNA) and crosslinking reaction of GMNA with hexamethylene diisocyanate biuret (HDIB). The Tg of crosslinked polymer was investigated by DSC. The orientation and stability of the poled and crosslinked polymer film were studied by UV-Vis spectra and Maker fringe method.

Thermal behavior of polyaniline (PAn) doped with kinds of inorganic or organic acids under desired atmosphere were studied by TG, DSC and in-situ electrical conductivity measurements. The reason for the thermal stability of electrical conductivity of doped PAn was discussed.

Aluminum solid electrolytic capacitors with polyaniline doped with inorganic and organic acids as counterelectrode were fabricated, their properties were studied.

Summary form only given. Macromolecular complex of polyaniline/sulfonated polystyrene (PAn/SPS) has been prepared. The complex in which the sulfonation degree of SPS is lower than 15mol% in doped state is soluble in N-methyl pyrrolidinone (NMP) or THF and its NMP or THF solution can be diluted by chloroform or pyridine. But once the sulfonation degree of SPS is over 15mol% the complex is insoluble in any solvents because of strong ionic cross-linking. The complex film in doped state can be directly prepared with solution casting. The electrical conductivity of the film ranges from 10/sup -8/ to 10/sup -4/S/cm. For PAn content below I0wt% the electrical conductivity increases with PAn content. Above I0wt%, it remains almost constant. The complex exhibits three absorption bands in UV-Vis spectra at 325, 430 and 750-800nm, respectively. The band at 750-800nm shifts toward longer wavelength with the increase of PAn content. When NMP solution of the complex is diluted with NMP, PAn is dedoped, but when it is diluted with THF, pyridine or cyclohexanone, PAn is still in doped state. PAn and SPS have good compatibility. Thermal stability of the complex is enhanced with increase of PAn content or conversion of SO/sub 3/H into SO/sub 3//sup -/.

The infrared spectra of soluble polyaniline (PAn) have been studied. It is found that the i.r. spectrum of the soluble PAn gives more structural information than those of insoluble samples. A tentative assignment is given based on the observed effects of HCl concentration in the polymerization system on the i.r. spectra of the PAn obtained and on the spectral changes during HCl or I2 doping and NH3 undoping.

Soluble polytoluidine was reacted with phenylhydrazine and iodine to obtain polytoluidines with different degrees of oxidation. Their reactions with HCl were followed by i.r. spectroscopy. Based on their spectral changes, a doping mechanism was proposed.