Electroluminescent device preparation

M. Onada and K. Yoshino, Heterostructure electroluminescent devices prepared from self-assembled monolayers of poly(/ -phenylene vinylene) and sulfo-nated polyaniline, Jpn. J. Appl. Phys. 54.L260 (1995). 

Another recently discovered form of epitaxy is graphoepitaxy (Geis et al. 1979). Here a non-crystalline substrate (often the heat-resistant polymer polyi-mide, with or without a very thin metallic coating) is scored with grooves or pyramidal depressions the crystalline film deposited on such a substrate can have a sharp texture induced by the geometrical patterns. More recently, this has been tried out as an inexpensive way (because there is no need for a monocrystalline substrate) of preparing oriented ZnS films for electroluminescent devices (Kanata et al. 1988). 

Morii, K. et al. 2000. Characterization of light-emitting polymer devices prepared by ink-jet printing. Proc. 10th Int. Workshop on Inorganic and Organic Electroluminescence. pp. 357-360. 

Fluorene-containing polymers and electroluminescent devices therefrom Fluorene-containing polymers and compounds useful in the preparation thereof... 

Pyrrolo[2,3-. ]pyridine zinc(ll) and A -(2-pyridyl)pyrrolo[2,3- ]pyridine zinc(ll) compounds have been prepared and characterized by X-ray crystallography <2000IC5248>. The pyrrolo[2,3- ]pyridine zinc compound, formed from pyrrolo[2,3-. ]pyridine and zinc acetate, is a stable compound that can produce a blue light in electroluminescent devices. 

Crosslinkable reactive mesogens, (VI), were prepared by O Neill et al. (3) for use in electroluminescent devices. Crosslinking occurred by cyclopolymerization as illustrated in Eq. (1). 

Mizusaki et al. (5) prepared triphenylamine copolymers, (VI), which had hole transport properties that were used in organic electroluminescent devices. 

Blue electroluminescent polymers and electroluminescent device were prepared by Sohn et al. (5) using poly(dioctylfluorene-co-indolocarbazole), (V). 

Doping of ionic electroluminescent films of [Ru(bpy)3]2+ with [Os(phen)3]2+ produced single layer OLEDs with luminescence emerging predominantly from the Os MLCT excited state, but the emission energy can be tuned to some extent by varying the concentration of the dopant. The devices prove to have better stability than devices prepared from either of the pure complexes [132],... 

In one recent study, Mn2+-doped CdS nanocrystals grown with a ZnS passivating shell were used as the recombination centers in direct current (dc) electroluminescent devices (104). The Mn2+ CdS/ZnS nanocrystals were prepared by the inverse micelle procedure (102) (see Section II.C) and these colloids were incorporated into a multilayer device structure by spin-coat... 

Aluminium-pyrazol-5-one derivatives, (I), prepared by Kathirgamanathan [1] were effective as white light emitters and used in organic electroluminescent devices. Bis(2-phenylimidazo[l,2-a]pyridinato-N,C)iridium derivatives, (II), prepared by Lussier [2] were effective as phosphorescent emission agents. 

Fluorene copolymers, (III), were prepared by Sohn [3] that offered improved emission efficiency and blue light color purity and were used in organo-electroluminescent devices. 

Regiogegular fluorcene, (IV), and carbazole polymers, (V), prepared by Heeney [4] and Leclerc [5], respectively, were useful as electroluminescent devices because of their solubility in organic solvents and ease of processability. 

Light-emitting fluorene polymers, (VI), displaying blue electroluminescence were prepared by Mullen [6] and used in electronic devices. 

Hexaalkylated phenyl monomer derivatives and pentaaromatic diamines were used by O Dell [5] to prepared conjugated polymers, (IX), which were used in electroluminescent devices. In a separate investigation by O Dell [6], terpo-lymers, (X), were also prepared. 

A single-step preparation of a new class of soluble co- and terpoly(arylene-oxadia-zole) polymers containing at least 20 repeat units have been prepared by the condensation of aromatic dicarboxylic acids with hydrazine hydro-chloride. Photoluminescence efficiencies of 50% were reported. Targeted applications include electroluminescent devices, photovoltaics, and diodes. 

Kambe [3] prepared electroluminescent devices containing two or more stacked organic layers, one of which consisted of an electron injecting an organic layer of conjugated poly(aryl-oxadiazole) derivatives, (111) and (IV). 

Thin films containing electron injecting layers of low crystalline oxadiazole derivatives, (V) and (VI), were prepared by Saitoh [4] and used in electroluminescence device. 

Electroluminescence devices derived from aniline trimers, (III), and phenyenediamine derivatives have also been prepared prepared and are described (2), (3). 

Figure 11.21 Proposed energy level diagram of the HOMO and LUMO energies of the materials used to prepare OLEDs based on Tb(tb-PMP)3(TPPO) [60]. (Reproduced with permission from S. Capecchi et al., High-efficiency organic electroluminescent devices using an organoterbium emitter, Advanced Materials, 2000, 12, 1591-1594. Wiley-VCH Verlag GmbH Co. KGaA.)...

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