NOVELTY - Fused cyclic compounds (I) are new.    USE - (I) are useful in manufacturing organic solar cell (claimed).    ADVANTAGE - (I) improve light efficiency, thermal stability and service life of the organic electronic device. The organic electronic device comprising an organic solar cell: has excellent characteristics; and has increased efficiency and reliability.    DETAILED DESCRIPTION - Fused cyclic compounds of formula (I) are new.    G = fused aliphatic ring, fused aromatic ring, N, O and/or S-containing fused aliphatic heterocyclic ring, N, O and/or S-containing fused aromatic heterocyclic ring, fused ring of aliphatic and aromatic rings, fused ring of N, O and/or S-containing aliphatic heterocyclic ring and N, O and/or S-containing aromatic heterocyclic ring, fused ring of hydrocarbon ring and N, O and/or S-containing heterocyclic ring, or C60-C84 fullerene (all are optionally substituted);    n = 2 or 3;    m = 1-3;    A = alkylene (optionally substituted); and    R = alkyl, cycloalkyl, alkoxy, aralkyl, aryl, alkylthio, arylthio, alkylsulfinyl, arylsulfinyl, alkenyl, silyl group, boron group, alkylamino, aralkylamino, arylamino, heteroarylamino, aryl, fluorenyl group, carbazolyl group, N, O and/or S-containing heterocyclyl (all are optionally substituted), H, deuterium, halo, cyano, nitro, imido, amido, OH, amino, thio, thioester group, ester group or carbonyl group.    INDEPENDENT CLAIMS are also included for:    (1) organic solar cell comprising a first electrode (102), a second electrode (105) placed opposite to the first electrode, and at least one organic material layer between the first electrode and the second electrode, where the organic material layer is composed of (I); and    (2) manufacturing an organic solar cell, comprising preparing a substrate (101), forming a first electrode on top of the substrate, forming at least one organic material layer composed of a photoactive layer (104) on top of the first electrode, and then forming a second electrode on top of the organic material layer, where the organic material layer is composed of (I).    DESCRIPTION OF DRAWING(S) - The diagram shows organic solar cell.    Substrate (101)    First electrode (102)    Hole transport layer (103)    Photoactive layer (104)    Second electrode (105)