TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Components: The organic thin film comprises an emission layer (130), a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer and/or a hole blocking film. (I) are included in a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer or emission layer. Preferred Definitions:    Ar3 = phenyl, naphthyl, anthracenyl, phenanthryl, naphthacenyl, pyrenyl, biphenylyl, para-terphenyl, meta-terphenyl, chrysenyl, triperylenyl, perylenyl, indenyl, furanyl, thiophenyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, oxazolyl, thiazolyl, oxadiazolyl, thiadiazolyl, pyridyl, pyrimidinyl, pyrazinyl, triazinyl, benzofuranyl, benzothiophenyl, benzimidazolyl, indolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, naphthydinyl, benzoxazinyl, benzthiazinyl, acridinyl, phenazinyl, phenothiazinyl or phenoxazinyl (all optionally substituted).    SPECIFIC COMPOUNDS - 477 Compounds (I) are specifically claimed e.g. dibenzofuran-4-yl-phenyl-(4-(9-phenyl-9H-carbazol-3-yl)-phenyl)-amine of formula (Ia), dibenzothiophen-4-yl-phenyl-(4-(9-phenyl-9H-carbazol-3-yl)-phenyl)-amine, dibenzofuran-2-yl-phenyl-(4-(9-phenyl-9H-carbazol-3-yl)-phenyl)-amine, dibenzothiophen-2-yl-phenyl-(4-(9-phenyl-9H-carbazol-3-yl)-phenyl)-amine, and (4-dibenzofuran-4-yl-phenyl)-phenyl-(4-(9-phenyl-9H-carbazol-3-yl)-phenyl)-amine.    EXAMPLE - 4-Bromo-dibenzofuran (5 g), sodium tert-butoxide (9.85 g) and tri-tetra-butylphosphine (0.12 g) were added to a flask and dissolved in toluene (200 ml), and bis(dibenzylideneacetone)palladium (0.12 g) was added and then refluxed and agitated for 12 hours under a nitrogen atmosphere. After the reaction completion, the reactant was extracted with ethyl acetate and distilled water. The organic layer was dried with magnesium sulfite and filtered. Then, the filtrate was concentrated under reduced pressure and purified, to obtain biphenyl-4-yl-dibenzofuran-4-yl-(4-(9-phenyl-9H-carbazol-3-yl)-phenyl)-amine (yield 91%).