NOVELTY - Substituted indole compounds (Q) are new.    USE - (Q) are useful in organic electroluminescent devices such as an organic LED, an organic solar cell, an organo photoreceptor and an organic thin film transistor, which are useful in an electronic device (all claimed) such as cellular phone, personal digital assistant, electronic dictionary, portable media player, remote controller, navigation system, game console, TV and computers.    ADVANTAGE - (Q) have excellent driving characteristic, rapid response speed and color reproduction range, and improves the luminous efficiency, electric current density, brightness, driving voltage, thermal resistance, chromatic purity and lifetime of the device.    DETAILED DESCRIPTION - Substituted indole compounds (Q) of formulae (I) and (II) are new.    R1-R12=Either (a) H, D, tritium, halo, (b) H, D, tritium, halo, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-aryl, 8-20C-alkenylaryl, 2-20C heterocyclic ring or optionally substituted 1-50C-alkyl including nitrile and acetylene, (c) H, D, tritium, halo, 1-20C-alkyl, 1-20C-alkoxy, 1-20C-alkylamine, 1-20C-alkyl thiophene, 6-20C-aryl thiophene, 2-20C-alkenyl, 2-20C-alkynyl, 3-20C-alkenyl, 6-20C-aryl, deuterium-substituted 6-20C-aryl, 8-20C-alkenyl aryl, silane, boron, germanium or optionally substituted 6-60C-aryl including 2-20C heterocyclic substituents, (d) H, D, tritium, halo, 1-20C-alkyl, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl amine, 6-60C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-aryl, 8-20C-alkenyl aryl, 2-20C-heterocyclic ring optionally substituted with hetero atom (O, N, S, Si or P) and including nitrile and acetylene, (e) H, D, tritium, halo, amino, nitrile, nitro, 1-20C-alkyl, 2-20C-alkenyl, 1-20C-alkoxy, 3-30C-alkenyl, 6-60C-aryl or optionally substituted 6-60C aryl amine including 2-60C heterocyclic substituents, (f) H, D, tritium, halo, 1-20C-alkyl, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl amine, 6-60C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-aryl, 8-20C-alkenyl aryl, 2-20C heterocyclic ring or optionally substituted 2-20C-alkenyl including nitrile and acetylene, (g) H, D, tritium, halo, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl, deuterium-substituted 6-20C-aryl, 7-20C alkyl aryl, 8-20C aryl alkenyl, 2-20C heterocyclic ring or optionally substituted 1-30C-alkoxy including nitrile and acetylene-based substituents, and (h) H, D, tritium, halo, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-alkyl aryl, 8-20C aryl alkenyl, 2-20C heterocyclic ring, optionally substituted 6-30C aryloxy nitrile and acetylene-based substituents; or    R1R2R3R4R5R6R7R8R9R10R11R12=optionally saturated ring; either    Ar1-Ar4=(a) H, D, tritium, halo, 1-20C-alkyl, 1-20C-alkoxy, 1-20C alkylamine, 1-20C alkyl thiophene, 6-20C aryl thiophene, 2-20C alkenyl, 2-20C alkynyl, 3-20C alkenyl, 6-20C aryl, deuterium-substituted 6-20C-aryl, 8-20C alkenyl aryl, silane, boron, germanium or optionally substituted 6-60C-aryl including 2-20C heterocyclic substituents, (b) H, D, tritium, halo, 1-20C-alkyl, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl amine, 6-60C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-aryl, 8-20C-alkenyl aryl, 2-20C-heterocyclic ring optionally substituted with hetero atom (O, N, S, Si or P) and including nitrile and acetylene, (c) H, D, tritium, halo, 1-20C-alkyl, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl amine, 6-60C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-aryl, 8-20C-alkenyl aryl, 2-20C heterocyclic ring or optionally substituted 2-20C-alkenyl including nitrile and acetylene, (d) H, D, tritium, halo, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl, deuterium-substituted 6-20C-aryl, 7-20C alkyl aryl, 8-20C aryl alkenyl, 2-20C heterocyclic ring or optionally substituted 1-30C-alkoxy including nitrile and acetylene-based substituents, (e) H, D, tritium, halo, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C aryl, deuterium-substituted 6-20C-aryl, 7-20C-aryl, 8-20C-alkenylaryl, 2-20C heterocyclic ring or optionally substituted 1-50C-alkyl including nitrile and acetylene or (f) H, D, tritium, halo, 2-20C-alkenyl, 1-20C-alkoxy, 6-20C-aryl, deuterium-substituted 6-20C-aryl, 7-20C-alkyl aryl, 8-20C-alkenyl aryl, 1-50C-alkyl, 2-20C heterocyclic ring or optionally substituted fluorene including nitrile and acetylene substituents; or    Ar1Ar2Ar3Ar4=optionally saturated ring; and    L=(a) nitro, nitrile, halo, 1-20C-alkyl, 1-20C-alkoxy or optionally substituted 6-60C-arylene including amino substituents, (b) nitro, nitrile, halo, 1-20C-alkyl, 1-20C-alkoxy or optionally substituted 6-60C-heteroarylene including amino substituents or (c) optionally substituted divalent aliphatic hydrocarbon.    INDEPENDENT CLAIMS are included for:    (1) an organic electroluminescent device comprising an organic layer including (Q); and    (2) an electronic device comprising the organic electroluminescent device and a control unit for driving the display device.