NOVELTY - A carbazole derivative (I), is new.    USE - New carbazole derivative is used for forming organic layer of organic electroluminescent device used in electronic device e.g. organic solar cell, organophotoreceptor, organic transistor, and illumination device (all claimed).    ADVANTAGE - The carbazole derivative provides organic electroluminescent device with excellent thermal resistance and durability, high luminous efficiency and chromatic purity, and low drive voltage.    DETAILED DESCRIPTION - A carbazole derivative of formula (I), is new.    Ar1,Ar2=6-60C aryl or fluorenyl;    L=group chosen from groups of formulae (ii)-(viii);    X=O or S;    m,p=0-3;    n,o=0-4;    R1-R4=D, halo, or 6-60C aryl, fluorenyl, 2-60C heterocyclyl containing heteroatom chosen from O, N, S, Si, or P, fused ring group of 6-60C aryl and 3-60C aliphatic ring, 1-50C alkyl, 2-20C alkenyl, 2-20C alkynyl, 1-30C alkoxy, 6-30C aryloxy, or -L'-N(R')(R") (all optionally substituted by group G);    L'=single bond, or 6-60C aryl, fluorenyl, fused ring group of 6-60C aryl and 3-60C aliphatic ring, or 2-60C heterocyclyl containing heteroatom chosen from O, N, S, Si, or P (all optionally substituted by group G);    R',R"=6-60C aryl, fluorenyl, fused ring group of 6-60C aryl and 3-60C aliphatic ring, or 2-60C heterocyclyl containing heteroatom chosen from O, N, S, Si, or P (all optionally substituted by group G);and    group G=halo, silanyl, siloxane, boron group, germanium group, cyano, nitro, 1-20C arylthio, 1-20C alkoxy, 1-20C alkyl, 2-20C alkenyl, 2-20C alkynyl, 6-20C aryl optionally substituted by H, 3-20C cycloalkyl, 7-20C arylalkyl, or 8-20C aryl alkenyl.    INDEPENDENT CLAIMS are included for the following:    (1) organic electroluminescent device (100); and    (2) electronic device.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of organic electroluminescent device.    Organic electroluminescent device (100)    Substrate (110)    Primary electrode (120)    Hole-injection layer (130)    Hole-transport layer (140)