TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: (I) is preferably 9-(4-naphthalen-2-yl-phenyl)-(1,7)phenanthroline, 9-(4-naphthalen-1-yl-phenyl)-(1,7)phenanthroline, 9-phenanthren-9-yl-(1,7)phenanthroline, 9-p-tolyl-(1,7)phenanthroline, 9-(4-tert-butyl-phenyl)-(1,7)phenanthroline, 9-(4-triphenylsilanyl-phenyl)-(1,7)phenanthroline, 9-m-tolyl-(1,7)phenanthroline, 9-(3-tert-butyl-phenyl)-(1,7)phenanthroline, 9-(3-triphenylsilanyl-phenyl)-(1,7)phenanthroline, 9-phenanthren-9-yl-8-phenyl-(1,7)phenanthroline or 9-phenanthren-9-yl-2-phenyl-(1,7)phenanthroline. (II) is preferably 4,4'-di(1,7-phenanthrolin-9-yl)biphenyl or 4,4'-bis(3-(biphenyl-3-yl)-1,7-phenanthrolin-9-yl)biphenyl. (I) or (II) comprises an electron transport layer and photoactive layer. The electron transport layer further comprises metal chelated oxinoid compounds including metal quinolate derivatives (including tris(8-hydroxyquinolato)aluminum, bis(2-methyl-8-quinolinolato)(p-phenylphenolato)aluminum, tetrakis-(8-hydroxyquinolato)hafnium or tetrakis-(8-hydroxyquinolato)zirconium), azole compounds (including 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole, or 1,3,5-tri(phenyl-2-benzimidazole) benzene), quinoxaline derivatives (including 2,3-bis(4-fluorophenyl)quinoxaline), and/or phenanthrolines (including 4,7-diphenyl-1,10-phenanthroline or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline). The photoactive layer comprises a host and a dopant. The photoactive layer further comprises a host material comprising bis-condensed cyclic aromatic compounds or anthracene derivatives. The anthracene derivative is of formula (An-L-An) or (A-An-A), preferably of formula (A1). The photoactive layer comprises a dopant of formula (Q-(N)n-(A3)2), ((A)2-(N)n-Q-(N)n-(A3)2), (Q-(N(A)2)3), substituted (E)-4,4'-(ethene-1,2-diyl)dianiline compounds of formula (B1), or substituted vinyl compounds of formula ((Y1)2-C=CH-Q1-CH=C(Y1)2), preferably N,N'-bis-(3,5-dimethyl-phenyl)-N,N'-bis-(4-isopropyl-phenyl)-chrysene-6,12-diamine, N,N,N',N'-tetra-p-tolyl-chrysene-6,12-diamine, 2-tert-Butyl-N9,N9,N10,N10-tetra-p-tolyl-anthracene-9,10-diamine, (E)-N,N'-(4,4'-(ethene-1,2-diyl)bis(4,1-phenylene))bis(N-(naphthalen-2-yl)naphthalen-2-amine), N,N,N',N'-tetraphenyl-anthracene-9,10-diamine, tris-(4-fluoro-4'-(trifluoromethyl)biphenyl-2,2'-diyl)iridium, or bis(5-tert-butyl-2-(isoquinolin-1-yl)phenyl)(2,2,6,6-tetramethyl-5-oxoheptan-3-yloxy)iridium, or bis(2,4-difluoro-6-(isoquinolin-1-yl)phenyl)(4-oxopentan-2-yloxy)iridium. In the device the ratio of host to dopant is 5:1-25:1, preferably 10:1-20:1.An = anthracene moiety (preferably mono- or di-phenylanthryl moiety);L = divalent connecting group (preferably -O-, -S-, -N(R)- or an aromatic group);A = aromatic group (preferably fused aromatic rings);R = not defined;A1, A2 = H, an aromatic group, or alkenyl;p, q = 1-3;A3 = 2-60C aromatic group;Q = single bond or 3-60C aromatic;n, m = 1-6;Y1 = 3-60C aromatic group; andQ1 = aromatic group, divalent triphenylamine residue, or single bond.