An organic light emitting device including: a substrate; a first electrode; a second electrode; and an organic layer interposed between the first electrode and the second electrode and including an emission layer, wherein one of the first electrode and the second electrode is a reflective electrode and the other is a semitransparent or transparent electrode, and wherein the organic layer includes a layer having at least one of the compounds having at least one carbazole group, and a flat panel display device including the organic light emitting device. The organic light emitting device has low driving voltage, excellent current density, high brightness, excellent color purity, high efficiency, and long lifetime.

A condensed cyclic compound represented by Formula 1:

##STR00001## wherein in Formula 1, Ar and R.sub.1 to R.sub.8 are the same as described in the specification.

A dielectric material, to a device comprising the dielectric material and to use of the dielectric material in the fabrication of a device. One dielectric material may comprise a halogen-based elastomer mixed with a halogen based surfactant and exhibiting electro-mechanical self-healing properties and/or an increased dielectric constant compared to the halogen-based elastomer. Another dielectric material may comprise a halogen-based polymer mixed with a halogen based surfactant and exhibiting an increased dielectric constant compared to the halogen-based polymer.

A light emitting device includes an emission layer disposed between electrodes. The emission layer includes a host and a delayed fluorescence dopant. The delayed fluorescence dopant includes a fused polycyclic compound represented by Formula 1:

##STR00001##

A series of 8-(bisphenylethynyl)-ester flexible multiple ring-containing fluoroboron pyrrole liquid crystal dyes are synthesized by introducing a diphenylethynyl rigid structure at position 8 of a boron-dipyrromethene core via a Sonogashira coupling reaction, and a flexible multiple ring such as bicyclohexane, or cholesterol is connected to the biphenylethynyl via an esterification reaction. The dye compounds all have maximum emission wavelengths in methylene chloride concentrated around 525 nm, present green fluorescence, and show good dichroic colour ratios and ordered parameters in E7 liquid crystal. The liquid crystal compounds are in a liquid crystal intermediate phase within the range of 100-280° C., and may be used for manufacturing liquid crystal display products, especially as guest dyes for guest-host mode liquid crystal displays. The response time can be improved and a rapid response effect achieved when the compounds are added to E7 liquid crystal and used for a guest-host display mode.

Provided is a compound having the structure: (SIG)-(SI-MOD).sub.m
where SIG is a signaling molecule, SI is a self-immolative structure bound to SIG such that SIG has a reduced signal relative to the signal of SIG without SI, MOD is a moiety bound to SI that is subject to modification by an activator, and m is an integer from 1 to about 10. When MOD is modified by an activator, SI is destabilized and self-cleaved from SIG such that SIG generates an increased signal. Also provided are methods of determining whether a sample, such as a cell, comprises an activator, such as a nitroreducase, using the compound. Further provided are methods of determining whether a mammalian cell is hypoxic using the compound where nitroreductase is the activator. A method of detecting a microorganism that comprises a nitroreductase using the compound where nitroreductase is the activator is also provided.

As an example of an EC element in which vertical color separation is suppressed, the present disclosure provides an EC element including a pair of electrodes, a solvent, an anodic EC compound, and a cathodic EC compound. In the EC element, the difference between a solvation free energy of an oxidized form of the anodic EC compound in water and a solvation free energy of the oxidized form in octanol is 35 kcal/mol or more, and the difference between a solvation free energy of a reduced form of the cathodic EC compound in propylene carbonate and a solvation free energy of the reduced form in octanol is −35 kcal/mol or less.

Provided are a heterocyclic compound represented by Formula 1-1 or 1-2, an organic light-emitting device including the heterocyclic compound, and an electronic apparatus including the organic light-emitting device:

##STR00001## wherein Formulae 1-1 and 1-2 are respectively the same as described in the present specification.

The invention relates to a an organic electroluminescent device comprising a light-emitting layer B comprising a host material H.sup.B, a first thermally activated delayed fluorescence (TADF) material EB, and an emitter material S.sup.B.

Bulk assemblies are provided, which may have desirable photoluminescence quantum efficiencies. The bulk assemblies may include two or more metal halides, and a wide band gap organic network. The wide band gap organic network may include organic cations. The metal halides may be disposed in the wide band gap organic network. Light emitting composite materials also are provided.