An organic electroluminescence device (1) includes an anode (3), a cathode (4), and an emitting layer disposed between the anode (3) and the cathode (4). The emitting layer includes a first emitting layer (51) and a second emitting layer (52). The first emitting layer (51) contains, as a first host material, a first compound that has at least one group represented by a formula (11) below and that is represented by a formula (1) below, where at least one of R.sub.101 to R.sub.112 is a group represented by the formula (11). The second emitting layer (52) contains a second compound represented by a formula (2) below as a second host material,

##STR00001##

An organic light emitting diode (OLED) includes at least one emitting material layer (EML) disposed between two electrodes and including a first compound of a pyrimidine-based organic compound substituted with at least one electron-withdrawing group and a second compound of an organic compound having a tetracene-based core. The OLED can be included in an organic light emitting device. The first compound and the second compound can be the same emitting material layer or adjacently disposed emitting material layers. The OLED can lower its driving voltage and improve its luminous efficiency utilizing the advantages of the first and second compounds by adjusting energy levels between the first and second compounds.

Ultra-narrow bandgap Non Fullerene Acceptors (NFAs) comprising an A-D-A′-D-A structure or an A-D-A′-D′-A′-D-A structure were designed, synthesized, and characterized (where A, A′ are organic acceptor moieties and D and D′ are organic donor moieties). Exemplary NFA materials have narrow bandgap (0.86 eV-0.99 eV). Photovoltaic devices and Near Infrared photodetector devices based on these compositions above were synthesized with controlled amounts of solvents and additives. A photodetector having a specific detectivity of 2.41×10.sup.12 Jones (D*) at a wavelength of 1040 nm was achieved.

A light emitting element includes a first electrode, a second electrode disposed on the first electrode, and an emission layer disposed between the first electrode and the second electrode. The emission layer may include a hole transporting host, an electron transporting host, a phosphorescent sensitizer, and a delayed fluorescent dopant. The delayed fluorescent dopant may have a greater absolute value of the HOMO energy level than the hole transporting host. Accordingly, the light emitting element including the delayed fluorescent dopant in an embodiment may exhibit long lifespan.

A compound of formula (I):
EAG-EDG-EAG   (I)
wherein each EAG is an electron accepting group; and EDG is an electron-donating group of formula (IIa): ##STR00001##
The compound of formula (I) may be used in a photosensitive layer of an organic photodetector wherein the photosensitive layer comprises the compound of formula (I) and an electron donor. A photosensor may comprise the organic photodetector and a light source, e.g. a near infra-red light source.

An organic EL device includes: an anode; a cathode; an anode side emitting unit; a cathode side emitting unit; a charge generating unit; a first organic layer having a thickness of 40 nm or less; and a second organic layer, in which the anode side emitting unit includes a first emitting layer which is provided close to the anode, a difference between an ionization potential Ip(H1) of a first host material in the first emitting layer and an ionization potential Ip(EBL) of a first organic material in the first organic layer satisfies a relationship of a numerical formula (Numerical Formula A1) below,

Ip(H1)−Ip(EBL)≤0.4 eV  (Numerical Formula A1).

Provided are compounds comprising a structure of the following Formula I:

##STR00001##

where the structure of Formula I can be coordinated to a metal M.

Also provided are formulations comprising these compounds. Further provided are OLEDs and related consumer products that utilize these compounds.

A compound for an organic optoelectronic device, a composition for an organic optoelectronic device including the same, an organic optoelectronic device, and a display device, the compound being represented by Chemical Formula 1:

##STR00001##

An iridium complex which has a phenylpyridine bidentate ligand containing a group represented by the following general formula (A): ##STR00001##
wherein X represents a cyano group or a halogenated alkyl group; L represents a single bond or a divalent linking group; R represents a substituent; n represents an integer of 0 to 4; * represents a binding site to a phenylpyridine bidentate ligand.

A light-receiving device in which an increase in driving voltage is inhibited is provided. Any of the following light-receiving devices is provided: a light-receiving device that includes a light-receiving layer between a pair of electrodes and in which the light-receiving layer includes an active layer, a buffer layer, and an electron-transport layer, the buffer layer is between the active layer and the electron-transport layer and is in contact with the active layer, and the buffer layer includes an organic compound having an electron-withdrawing group; a light-receiving device that includes a light-receiving layer between a pair of electrodes and in which the light-receiving layer includes an active layer, a buffer layer, and an electron-transport layer, the buffer layer is between the active layer and the electron-transport layer and is in contact with the active layer, and the buffer layer includes a heteroaromatic compound having an electron-withdrawing group.