A fluorescent infrared emitting composition comprising a mixture of a first material and a second material wherein the first material is a fluorescent infrared material and the second material is a fluorescent material having a higher photoluminescent quantum yield (PLQY) and shorter peak wavelength than the infrared emitting material. The composition may be used as the light-emitting layer of an organic light-emitting device.

A light-emitting composition comprising: a light-emitting group and a polymer comprising: a repeat unit of formula Ar.sup.1 wherein Ar.sup.1 is an arylene repeat unit which is unsubstituted or substituted with one or more substituents; and a repeat unit of formula (I): (I) wherein Ar.sup.2 and Ar.sup.3 each independently represent a C.sub.6-20 arylene group or a 5-20 membered heteroarylene group which is unsubstituted or substituted with one or more substituents and CB represents a conjugation-breaking group which does not provide a conjugation path between Ar.sup.2 and Ar.sup.3; wherein the polymer has a solubility in water or a C.sub.1-8 alcohol at 20° C. of at least 0.1 mg/ml. The composition may be a light-emitting polymer in which the polymer contains the light-emitting group. The light-emitting composition may be part of a particle containing the polymer and a matrix material, e.g. silica. The light-emitting composition may be used in an assay for detection of a target analyte.

A polymer and a light-emitting device employing the same are provided. The polymer includes a first repeat unit with a structure represented by Formula (I):

##STR00001##

wherein the definitions of R.sup.1, R.sup.2, A.sup.1, A.sup.2, A.sup.3, and Z.sup.1 and n are as defined in the specification. At least one of A.sup.1, A.sup.2, and A.sup.3 is not hydrogen.

The invention relates to novel organic semiconducting compounds containing a polycyclic unit, to methods for their preparation and educts or intermediates used therein, to compositions, polymer blends and formulations containing them, to the use of the compounds, compositions and polymer blends as organic semiconductors in, or for the preparation of, organic electronic (OE) devices, especially organic photovoltaic (OPV) devices, perovskite-based solar cell (PSC) devices, organic photodetectors (OPD), organic field effect transistors (OFET) and organic light emitting diodes (OLED), and to OE, OPV, PSC, OPD, OFET and OLED devices comprising these compounds, compositions or polymer blends.

A polymer comprising

##STR00001##

In this polymer, R, R′, and R″ are independently selected from the group consisting of: H, Cl, F, CN, alkyl, alkoxy, alkylthio, ester, ketone and aryl groups. Additionally, in this polymer X and X′ are independently selected from aryl groups. Finally, m independently ranges from 1 to 100 and n independently ranges from 0 to 99

Described are conjugated polymers and conjugated polymer nanoparticles formed therefrom. The conjugated polymers and conjugated polymer nanoparticles have a maximum emission of light that occurs within a tissue transparent window of the electromagnetic spectrum. These emission properties are particle-size independent. The sizes of the conjugated nanoparticles are controlled by altering the concentration of the conjugated polymer used to make conjugated polymer nanoparticles. Also described are methods of making conjugated polymer nanoparticles that have larger sizes than have been traditionally reported, involving a modified reprecipitation approach. The conjugated polymers and/or conjugated polymer nanoparticles can be used as fluorescent probes in biological imaging.

A compound having the following formula:

##STR00001##

which can also be embedded into a conjugated oligomeric of polymeric backbone, is proposed for optical and electro optical applications.

There is provided an electroactive material having Formula I

##STR00001##

wherein: Q is the same or different at each occurrence and can be O, S, Se, Te, NR, SO, SO.sub.2, or SiR.sub.3; R is the same or different at each occurrence and can be hydrogen, alkyl, aryl, alkenyl, or alkynyl; and R.sup.1 through R.sup.6 are the same or different and can be hydrogen, alkyl, aryl, halogen, hydroxyl, aryloxy, alkoxy, alkenyl, alkynyl, amino, alkylthio, phosphino, silyl, —COR, —COOR, —PO.sub.3R.sub.2, —OPO.sub.3R.sub.2, or CN.

The present invention relates to a plurality of host materials and an organic electroluminescent device comprising the same. By comprising a specific combination of a plurality of host compounds, the organic electroluminescent device according to the present invention provides high efficiency and a long lifespan.

According to one embodiment, the organic electroluminescent device includes an anode, a cathode provided apart from the anode, and a luminous layer. The luminous layer is disposed between the anode and the cathode and contains a host material and a luminous dopant. The host material includes a polymer having a skeleton represented by Formula 1 below in a repeating unit, and a number of repetitions being 20 to 10,000. ##STR00001## (X is an element composing a polymer backbone, R1, R2, R3, and R4 may be identical or different, and each of them is selected from a hydrogen atom, an alkyl group, an aromatic ring group, an alkoxy group, an alkothio group, and a halogen atom.)