An organic electroluminescent (EL) element includes: a first electrode; an interlayer formed above the first electrode; an organic light-emitting layer formed using the interlayer as a foundation; and a second electrode formed above the organic light-emitting layer. The organic light-emitting layer contains at least a host material and a dopant material. The interlayer is formed using a material which has an energy gap larger than an energy gap of the dopant material and a highest occupied molecular orbital (HOMO) level deeper than a HOMO level of the dopant material.

A composition comprising a phosphorescent compound of formula (I) and a polymer comprising a repeat unit of formula (II) Ar.sup.1 is an aryl or heteroaryl group. R.sup.2 is a substituent. A is independently in each occurrence N or CR.sup.3 wherein R.sup.3 is H or a substituent. M is a transition metal or metal ion. x is a positive integer of at least 1. y is 0 or a positive integer. L.sup.1 is a mono- or polydentate ligand. R.sup.1 is a substituent. z is 0 or a positive integer. X is O or S. The phosphorescent compound of formula (I) may be mixed with the polymer or may be covalently bound thereto. The composition may be used in the light-emitting layer of an organic light-emitting device.

The present invention relates to organic copolymers and organic semiconducting compositions comprising these materials, including layers and devices comprising such organic semiconductor compositions. The invention is also concerned with methods of preparing such organic semiconductor compositions and layers and uses thereof. The invention has application in the field of printed electronics and is particularly useful as the semiconducting material for use in formulations for organic thin film-transistor (OFET) backplanes for displays, integrated circuits, organic light emitting diodes (OLEDs), photodetectors, organic photovoltaic (OPV) cells, sensors, memory elements and logic circuits.

A solid state light-emitting device comprising: a first electrode coupled to a first charge injecting layer; a second electrode coupled to a second charge injecting layer; an emissive layer comprising a perovskite material, wherein the emissive layer is provided between the first and second charge injecting layers; and wherein the bandgaps of the first and second charge injecting layers are larger than the bandgap of the emissive perovskite layer.

A semiconducting composition comprising a semiconducting polymer and a semiconducting non-polymeric polycyclic compound, wherein the semiconducting polymer comprises units of A and/or B: ##STR00001##
wherein R.sub.1, R.sub.2, R.sub.5, R.sub.6, R.sub.7, R.sub.8, x, y, p, q, r, R.sub.3, R.sub.4, R.sub.9, R.sub.10 and R.sub.11 have any of the meanings defined in the description.

A polymer compound is provided having a constitutional unit represented by the following formula (1): ##STR00001##
wherein: R.sup.1 and R.sup.2 represent an alkyl group, an aryl group, a mono-valent aromatic heterocyclic group, an alkoxy group or an aryloxy group, and Ar.sup.1 represents an arylene group or a di-valent condensed polycyclic aromatic heterocyclic group.

The present invention relates to novel compositions comprising one or more polymeric organic semiconducting (OSC) compounds and one or more organic solvents. The composition preferably comprises 3,4-dimethyl anisole as solvent. Furthermore, the present invention describes the use of these compositions as inks for the preparation of organic electronic (OE) devices, especially organic photovoltaic (OPV) cells and organic light emitting diodes (OLED) devices, to methods for preparing OE devices using the novel formulations, and to OE devices, OLED devices and OPV cells prepared from such methods and formulations.

Metallopolymers of formula (I) where R.sup.1 and R.sup.1′; and R.sup.2 and R.sup.2′ are independently of each other, a C.sub.2-C.sub.10 alkyl group; X is CR3R3′ or NR4; R.sup.3 and R.sup.3′ are, independently of each other, as is R.sup.4, a C.sub.2-C.sub.10 alkyl group; L is a C.sub.4-C.sub.10 alkylene group; Ln.sup.1 and Ln.sup.2 are, independently of each other, chosen from the lanthanide cations; L.sup.1 and L.sup.2 are, independently of each other, chosen from the α-diketonate ligands; T is a neutral bidentate Lewis base including two coordinating nitrogen atoms; .fwdarw. represents a coordination of group T via the two nitrogen atoms of T to Ln.sup.1 and Ln.sup.2 respectively; Ln.sup.1 and Ln.sup.2 are, independently of each other, chosen from the lanthanide cations; L.sup.1 and L.sup.2 are, independently of each other, chosen from the β-diketonate, picolinate or dipicolinate monoanionic ligands; 0.01<x<0.50; 0<y<0.49, with x+y=0.50.

There is disclosed a method for preparing a modified electrode for an organic electronic device, wherein said modified electrode comprises a surface modification layer, comprising: (i) depositing a solution comprising M(tfd).sub.3, wherein M is Mo, Cr or W, and at least one solvent onto at least a part of at least one surface of said electrode; and (ii) removing at least some of said solvent to form said surface modification layer on said electrode.

The invention relates to new conjugated semiconducting polymers containing thermally cleavable side groups. The thermally cleavable side groups are selected from among carbonate groups and carbamate groups, By thermally cleaving side groups, the solubility or the polymers can he reduced in a targeted manner. The polymers are used as semiconductors in organic electronic (OE) devices, especially in organic photovoltaic (OPV) devices, organic photodetectors (OPDs), organic light emitling diodes (OLEDs), and organic field effect transistors (OFETs).