Provided are (i) a solution for forming an organic semiconductor layer which solution has an excellent coating property, (ii) an organic semiconductor which is produced with use of the solution and which has high heat resistance, (iii) a layer which contains the organic semiconductor, and (iv) an organic thin film transistor which exhibits high electrical properties. A composition containing: an organic semiconductor; and a polymer (1) having at least one unit selected from the group consisting of units represented by formulae (1-a), (1-b), and (1-c). A composition containing the organic semiconductor, the polymer (1), and an organic solvent can be suitably used as a solution for forming an organic semiconductor layer.

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 method of forming a metallic pattern on a substrate is provided. The method includes applying onto a metallic surface, a chemically surface-activating solution having an activating agent that chemically activates the metallic surface; non-impact printing an etch-resist ink on the activated surface to produce an etch resist mask according to a predetermined pattern, wherein at least one ink component within the etch-resist ink undergoes a chemical reaction with the activated metallic surface to immobilize droplets of the etch-resist ink when hitting the activated surface; performing an etching process to remove unmasked metallic portions that are not covered with the etch resist mask; and removing the etch-resist mask.

The present invention provides methods for purifying a layer of carbon nanotubes comprising providing a precursor layer of substantially aligned carbon nanotubes supported by a substrate, wherein the precursor layer comprises a mixture of first carbon nanotubes and second carbon nanotubes; selectively heating the first carbon nanotubes; and separating the first carbon nanotubes from the second carbon nanotubes, thereby generating a purified layer of carbon nanotubes. Devices benefiting from enhanced electrical properties enabled by the purified layer of carbon nanotubes are also described.

An ink for forming a functional layer, which is used when any thin film layer among functional layers consisting of a plurality of thin film layers is formed, includes a functional layer forming material and a solvent for dissolving the functional layer forming material, and in which the number of particles of 0.5 μm or more is 7 or less in 10 ml of the ink for forming a functional layer.

The invention relates to methods for fabricating an optoelectronic device, including: directly applying a printing ink composition to a patterning process, wherein the printing ink composition includes (1) at least one compound selected from the group of compounds represented by Chemical Formula 1, Chemical Formula 2, Chemical Formula 3, and mixtures thereof as disclosed herein in an amount of 0.01-90 wt % based on the total weight of the composition and (2) at least one material for an optoelectronic device.

A polymer compound having an excellent crosslinking ability is provided. The polymer compound has at least one terminal constitutional unit represented by the formula (1) and a constitutional unit represented by the formula (2):

##STR00001##

In the constitutional unit represented by formula (1), mT represents an integer of 0 to 5, nT represents an integer of 1 to 4, cT represents an integer of 0 to 1, Q.sup.T represents a crosslinkable group, K.sup.T represents an alkylene group or the like and Ar.sup.T represents an aromatic hydrocarbon group or the like. In the constitutional unit represented by formula (2), mA represents an integer of 0 to 5, n represents an integer of 1 to 4, Ar.sup.1 represents an aromatic hydrocarbon group or the like, K.sup.A represents an alkylene group or the like and Q.sup.1 represents a crosslinkable group.

Disclosed is a fluorine-containing composition containing a fluorine-containing compound represented by general formula (1) and a fluorine-based solvent.

##STR00001##

A composition for forming an organic semiconductor film includes an organic semiconductor represented by the following Formula A-1, and a solvent having a boiling point of from 150° C. to 300° C. and an SP value of from 15.0 to 18.0.

##STR00001##

A method of fabricating a large-area perovskite film includes steps of: providing a precursor solution on a conductive substrate to form a film, wherein the perovskite is represented by a formula of ABX.sub.3, and the solutes of the precursor solution at least comprises A, B and X; and applying an anti-solvent or Infrared light on the film. The fabrication methods of a large-area perovskite film and a perovskite solar cell or module are also disclosed.