Organic electroluminescent (EL) devices with multilayered thin-film structures which emitted bright blue light were constructed. Two empirical guides for the selection of blue-emitting materials established. The keys to obtain EL cells high efficiency excellent film-forming capability an emitter layer and appropriate combinations carrier transport avoiding formation exciplexes. In one our organic devices, emission a luminance 700 cd/m2 was achieved at current density 100 mA/cm2 dc drive voltage 10 V.

Using the combination of a layered perovskite compound (C6H5C2H4NH3)2PbI4 (PAPI), which forms stable exciton with large binding energy owing to its low-dimensional semiconductor nature and exhibits sharp strong photoluminescence from band, an electron-transporting oxadiazole derivative, we fabricated organic–inorganic heterostructure electroluminescent (EL) device. The EL spectrum device corresponded well PAPI film; emission was peaking at 520 nm half-width about 10 liquid-nitrogen...

We have succeeded in fabricating a novel thin-film electroluminescent device with luminescent hole transport layer as an emitter. The cell structure is composed of indium-tin-oxide substrate, (emitter), electron layer, and MgAg electrode. most essential feature our owes for adoption oxadiazole derivative layer. emission intensity 1000 cd/m2 was achieved at current 100 mA/cm2.

We have succeeded in the fabrication of a stable organic electroluminescent (EL) device with three-layer structure; hole transport layer/emitting layer/electron layer. The EL was prepared by vacuum evaporation. Efficient carrier double injection into emitting layer realized use separate and electron layers. Bright emission observed darkened room at dc bias voltage 50 V. Stable lasted for more than five hours this condition. spectrum could be changed variation material

Organic electroluminescent devices with a double-heterostructure indium-tin-oxide substrate/hole transport layer/emitter layer/electron layer/MgAg have been fabricated by vacuum vapor deposition. The organic carrier and emitter layers were composed of amorphous films. In the devices, luminance continued to lie in high level, even when thickness was 50 Å. confinement charge carriers molecular excitons within narrow layer achieved.

An electroluminescent device with a three-layer structure was constructed using an intensely fluorescent material, 12-phthaloperinone derivative, for the emitter material. The cell of Mg-electrode/amorphous electron-transport layer/polycrystalline emitting layer/amorphous hole-transport layer/Au-electrode on glass substrate. Yellow EL emission clearly observed in normal room lighting at dc bias voltage 60 V. intensity proportional to injection current over wide range 10 -7 -3 A/cm 2 ....

An electroluminescent diode with a microcavity structure which comprised reflective Ag anode (36 nm), hole transport dye layer (250 an emission laser (15 electron (240 and MgAg cathode was fabricated. A without the transparent ITO also prepared for reference. The driven in electric excitation mode spectra at fixed detection angles were measured together angular dependence of intensity wavelengths. sharpening marked alteration patterns observed.

Multilayer thin-film electroluminescent devices with blue emission color have been fabricated using new oxadiazole dimer dyes for both and electron transport layers. Emission characteristics of three types cells, SH-A: ITO/HTL/EML/MgAg, SH-B: ITO/EML/ETL/MgAg DH: ITO/HTL/EML/ETL/MgAg, in which ITO, HTL, EML, ETL MgAg represent indium-tin-oxide cathode, hole layer, layer magnesium-silver alloy anode, respectively, are compared. Luminances exceeding 1000 cd/m 2 observed peaks located at...

Oriented sexiphenyl (6P) film was prepared through epitaxial growth on rubbed substrates by vacuum deposition. Polarized absorption spectra demonstrated that the long axis of 6P molecule highly oriented along rubbing direction. Using 6P, we fabricated electroluminescent (EL) devices consisting indium-tin-oxide anode, emissive layer electron-transporting an oxadiazole derivative, and MgAg alloy cathode. Owing to orientation molecules, EL polarized in direction observed devices.

An optical microcavity structure was introduced into organic three-layer electroluminescent (EL) diodes with a europium complex as an emission layer. The device consisted of dielectric reflector composed SiO2/TiO2 bilayers, indium-tin-oxide electrode, hole transport layer, electron and MgAg electrode. the metal electrode constituted planer microcavity. Sharply directed from observed when operated under dc drive voltage. Both angular dependences intensity emitted light spectra EL were...

Abstract Glass transition phenomena in several polymers were studied by dielectric and dilatometric measurements. The measurements made over the frequency range of 10 −4 or −1 to 6 cycles/sec. temperature glass transition. In study, volume relaxation curves vs. curve obtained. three amorphous polymers, (polyvinyl acetate, polystyrene, polymethyl methacrylate), depends upon rate cooling seems be an apparent crystallizable (vinylidene chloride‐vinyl chloride copolymer, polyethylene...

Abstract Molecular motions in poly(vinylidene fluoride) were studied by the dielectric technique. Three distinct absorption peaks (α c , α a and β) observed frequency range from 0.1 cps to 300 kcps temperature −66 100°C. The molecular mechanisms for these absorptions their dependence are discussed, results compared with x‐ray diffraction NMR measurements. It is concluded that located at 97°C (1 kcps) related motion crystalline region. −27°C can be interpreted as due micro‐Brownian of...

Abstract The dielectric properties and the d. c. conductivity of poly(vinyl chloride), acetate), polychlorotrifluoroethylene, poly(ethylene terephthalate) were measured at temperatures above below glass transition temperature various pressures up to 3000 atm. α relaxation associated with micro‐Brownian motion amorphous chain segments depends strongly upon pressure, while β due local‐mode frozen main shows weak dependence on pressure. It is found that free volume concept valid for description...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh molecular weight linear polyethylenimine and poly(N-methylethylenimine)Ryuichi Tanaka, Isao Ueoka, Yasuhiro Takaki, Kazuya Kataoka, Shogo SaitoCite this: Macromolecules 1983, 16, 6, 849–853Publication Date (Print):June 1, 1983Publication History Published online1 May 2002Published inissue 1 June 1983https://pubs.acs.org/doi/10.1021/ma00240a003https://doi.org/10.1021/ma00240a003research-articleACS PublicationsRequest reuse permissionsArticle...

Abstract Dielectric properties of four methacrylate polymers (methyl, ethyl, n ‐butyl and ‐octyl) were studied in the frequency range 0.0001 cps–300 kcps at temperatures above below glass transition temperature various pressures up to 2500 atm. At well T g a single relaxation peak (α′ peak) was observed case higher ‐alkyl methacrylates. However, this split into two peaks, α β, with decrease or increase pressure. The molecular motions corresponding β processes are micro‐Brownian amorphous...

Charge drift mobilities of five oxadiazole derivatives doped in polycarbonate (PC) were evaluated with the time-of-flight technique. It is demonstrated that oxadiazoles incline to having electron-transport characteristics. In particular, an naphthyl substituent (BND) was found possess high potential electron transport; mobility 50 wt % BND PC 2.2×10−5 cm2 V−1 s−1 at electric field 7.5×105 V cm−1 room temperature. addition, incorporating strong electron-releasing substituents into add hole...

S. Yamada, Tokito, T. Tsutsui and Saito, J. Chem. Soc., Commun., 1987, 1448 DOI: 10.1039/C39870001448

The electrical properties of silver doped As-Se glasses up to 1.0 atomic % have been studied. d.c. conductivity the is represented by a single activation energy which smaller than that parent glass. at room temperature increases with increase content. However glass containing amount less conductive above certain temperature. Pressure dependence shows electronic and ionic characteristics. A dielectric relaxation closely related conduction found. Above results can be formation defects contain silver.

The observation is made that a straight line with slope of 1 obtained when the two parameters Gibbs—DiMarzio theory are plotted against each other. Δε/k, energy difference between trans and gauche conformations hydrocarbon-type polymer chain, 2α/k, ``hole formation energy.'' identity (practically within experimental error) these implies free volume V0 at Tg apparently constant since both 2α/k Δε/k functions alone. Furthermore, product TgΔα (where Δα in cubic expansion coefficients above...

Abstract The dielectric properties of three kinds polymonochlorotrifluoroethylene having various degrees crystallinity were studied. measuring instruments by which the can be measured over a wide range frequency are briefly described. measurements for samples made 0.1 to 10 6 cycles/sec. and temperature −50 140°C. main conclusions from experimental results as follows. Two dispersions observed would due polar groups in amorphous regions. At melting temperature, positions two coincide with...

The adsorption isotherm of water vapor on nonalkali glass cloth was obtained at 25°C, and its dielectric power factor measured also in the frequency range 80 kc/sec∼11 mc/sec. surface dc conductivities glass, soda fused silica, Teflon, polymethylmethacrylate plates increased rapidly to maximum peaks, when they were exposed vapor, then gradually decreased certain constant values. These phenomena may be interpreted as physical picture phase changes adsorbed from amorphous state crystalline...