NOVELTY - Fluorene-derivative as organic electroluminescent compound is new.    USE - In an organic electroluminescent device or organic solar cell (claimed).    ADVANTAGE - The electroluminescence device is self-luminescent display devices showing the advantage of wide angle of view, excellent contrast and rapid response rate; and has excellent luminous efficiency and noticeable improved lifetime. The compound (I) provides excellent electroluminescent properties, longer device life and appropriate color coordinate, as compared to those conventional dopant materials; shows good luminous efficiency and excellent color purity and life property of material, so that organic light emitting diodes (OLED's) having very good operation life can be manufactured.    DETAILED DESCRIPTION - Fluorene-derivative of formula (I) as organic electroluminescent compound is new.    L1=group of formula (i) or (ii);    A,B1=chemical bond, group of formulae -C(R21)=C(R22)-, (iii) or (iv);    Ar1,Ar2=chemical bond, (6-60C)arylene, (3-60C)heteroarylene, 5- or 6-membered heterocycloalkylene containing at least one heteroatom selected from N, O or S, (3-60C)cycloalkylene, (2-60C)alkenylene, (2-60C)alkynylene, (1-60C)alkylenoxy, (6-60C)arylenoxy or (6-60C)arylenethio (all optionally substituted by halo, (1-60C)alkyl, halo(1-60C)alkyl, (6-60C)aryl, (3-60C)heteroaryl, 5- or 6-membered heterocycloalkyl containing at least one heteroatom selected from N, O, S or Si, (3-60C)cycloalkyl, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl, tri(6-60C)arylsilyl, adamantyl, (7-60C)bicycloalkyl, (2-60C)alkenyl, (2-60C)alkynyl, (1-60C)alkoxy, cyano, (1-60C)alkylamino, (6-60C)arylamino, (6-60C)ar(1-60C)alkyl, (6-60C)aryloxy, (6-60C)arylthio, (1-60C)alkoxycarbonyl, carboxyl, nitro or OH);    ring A1=group of formula (v) or (vi);    R1-R26, R31-R45=H, halo, (1-60C)alkyl, (6-60C)aryl, (3-60C)heteroaryl, t1 (all optionally substituted by T1) or t2;    t1=5- or 6-membered heterocycloalkyl containing at least one heteroatom selected from N, O or S, (3-60C)cycloalkyl, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl, tri(6-60C)arylsilyl, adamantyl, (7-60C)bicycloalkyl, (2-60C)alkenyl, (2-60C)alkynyl, (1-60C)alkoxy, cyano, (1-60C)alkylamino, (6-60C)arylamino;    t2=(6-60C)ar(1-60C)alkyl, (6-60C)aryloxy, (6-60C)arylthio, (1-60C)alkoxycarbonyl, carboxyl, nitro or OH;    T1=halo, (1-60C)alkyl (optionally substituted by halo), (3-60C)heteroaryl (optionally substituted by (6-60C)aryl, (6-60C)aryl, t1 or t2;    X1,X2,Y1,Y2=chemical bond, -C(R31)(R32)-, -N(R33)-, -S-, -W, -Si(R34)(R35)-, -P(R36)-, -C(=O)-, -B(R37)-, -In(R38)-, -Se-, -Ge(R39)(R40)-, -Sn(R41)(R42)-, -Ga(R43)- or -(R44)C=C(R45)-;    m,n=0-4;    -Ar-A-L1-B1-Ar2-=group of formula (vii).    R1-R20 optionally linked to an adjacent substituent via (3-60C)alkylene or (3-60C)alkenylene with or without a fused ring to form an alicyclic ring, or monocyclic or polycyclic aromatic ring; R31 and R32, R34 and R35, R39 and R40, R41 and R42, or R44 and R45 optionally linked via (3-60C)alkylene or (3-60C)alkenylene with or without a fused ring to form an alicyclic ring, or a monocyclic or polycyclic aromatic ring. Provided that when -Ar-A-L1-B1-Ar2- represent the group (vii), both X1 and X2 represents NR33 and both Y1 and Y2 represent a chemical bond, then R33 does not represent H or (1-5C)alkyl. INDEPENDENT CLAIMS are included for the following:    (1) an organic electroluminescent device comprising first electrode; second electrode; and at least one organic layer interposed between the first electrode and the second electrode, where the organic layer comprises the compound (I) and at least one host selected from compound of formulae (Ar10)a-X-(Ar20)b (II) or (Ar30)c-Y'-(Ar40)d (III); and    (2) an organic solar cell comprising the compound (I).    X=(6-60C)arylene or (4-60C)heteroarylene;    Y'=anthracenylene;    Ar10-Ar40=(4-60C)heteroaryl, (5-60C)cycloalkyl or (6-60C)aryl (all optionally substituted by (6-60C)aryl or (4-60C)heteroaryl (optionally substituted by (1-60C)alkyl (optionally substituted by halo), (1-60C)alkoxy, (3-60C)cycloalkyl, halo, cyano, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl or tri(6-60C)arylsilyl)), (1-60C)alkyl (optionally substituted by halo), (1-60C)alkoxy, (3-60C)cycloalkyl, halo, cyano, tri(1-60C)alkylsilyl, di(1-60C)alkyl(6-60C)arylsilyl, tri(6-60C)arylsilyl), H, (1-60C)alkyl, (1-60C)alkoxy or halo;    a,b,c,d=0-4.