The present invention relates to providing fluorescent silica nanoparticles having high luminance even when many fluorescent dyes are contained in silica particles. Fluorescent silica nanoparticles according to the present invention is fluorescent silica nanoparticles including silica nanoparticles and fluorescent dyes contained in the silica nanoparticles, in which a total volume of the fluorescent dyes is 5% or more with respect to a total volume of the fluorescent silica nanoparticles, and an emission quantum yield of the fluorescent silica nanoparticles is 10% or more.

Provided is an organic light emitting device comprising a light emitting layer comprising a compound of Chemical Formula 1 and a compound of Chemical Formula 2:

##STR00001## wherein: Ar.sub.1, Ar.sub.2, Ar.sub.4 and Ar.sub.5 are each independently a substituted or unsubstituted C.sub.6-60 aryl or C.sub.2-60 heteroaryl containing N, O or S; Ar.sub.3 is hydrogen, or a substituted or unsubstituted C.sub.6-60 aryl or C.sub.2-60 heteroaryl containing N, O or S; L.sub.1 to L.sub.3 are each independently a single bond or a substituted or unsubstituted C.sub.6-60 arylene; L.sub.4 to L.sub.6 are each independently a single bond or a substituted or unsubstituted C.sub.6-60 arylene or C.sub.2-60 heteroarylene containing N, O or S; L.sub.7 is a substituted or unsubstituted C.sub.6-60 arylene; R.sub.1 is hydrogen, deuterium, or a substituted or unsubstituted C.sub.6-60 aryl or C.sub.2-60 heteroaryl containing one or of N, O and S; a is 0 to 7.

Provided is an organic light-emitting device including a first electrode; a second electrode; and an organic layer between the first electrode and the second electrode and comprising an emission layer, wherein the organic layer includes at least one condensed cyclic compound represented by Formula 1.

An organic electroluminescence device of an embodiment includes a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region, wherein the hole transport region includes a diamine compound represented by Formula 1, thereby showing high emission efficiency:

##STR00001##

Provided are a light-emitting device and an electronic apparatus. The light-emitting device includes a first electrode, a second electrode facing the first electrode, and an interlayer disposed between the first electrode and the second electrode. The interlayer includes an emission layer and an electron blocking layer, the electron blocking layer includes a first electron blocking layer and a second electron blocking layer. The first electron blocking layer includes a first compound, the second electron blocking layer comprises a second compound, and the first compound is different from the second compound.

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 compound represented by the following formula (1A) or (1B):

##STR00001##

(the symbols in the formulae (1A) and (1B) have the same meaning as defined in the specification), an organic electroluminescent device containing the compound, and an electronic device including the organic electroluminescent device.

A plastic scintillator includes a polymeric matrix comprising a primary fluorophore capable of forming an amorphous glass in its pure form. The primary fluorophore is also capable of generating luminescence in the presence of ionizing radiation and includes: a central species including silicon; a luminescent organic group bonded to the central species or to an optional organic linker group, the luminescent organic group including fluorene or an analog thereof; and the optional organic linker group, if present, is bonded to the central species and the luminescent organic group.

The present disclosure relates to an organic electroluminescent compound and an organic electroluminescent device comprising the same. By using the organic electroluminescent compound of the present disclosure, an organic electroluminescent device having high luminous efficiency and/or long lifespan properties can be provided compared to conventional organic electroluminescent devices.

An organic electroluminescence device includes: an anode; an emitting layer; and a cathode, the emitting layer containing a first material, a second material and a third material, the first material being a fluorescent material, the second material being a delayed fluorescent material, the third material having a singlet energy larger than a singlet energy of the second material.