NOVELTY - An organic photoelectric transducer (10) has bulk heterojunction layer arranged between transparent electrode and counter electrode, and low molecular weight compounds (I, II, III and/or IV). The low molecular weight compound has molecular weight of 300-3000.    USE - Organic photoelectric transducer is used for solar cell and optical sensor array (both claimed).    ADVANTAGE - The organic photoelectric transducer has high conversion efficiency, durability, and can be manufactured economically.    DETAILED DESCRIPTION - An organic photoelectric transducer has bulk heterojunction layer arranged between transparent electrode and counter electrode, and low molecular weight compounds of formulae:(N1-(D1)p)s-(A1)q (I), (N1-(A1)p)s-(D1)q (II), (N1-(D1)p-(A1)q)s-(D2)r (III) and/or (N1-(A1)p-(D1)q)s-(A2)r (IV). The low molecular weight compound has molecular weight of 300-3000.    D1,D2=optionally substituted aromatic rings whose highest occupied molecular orbital is less than the highest occupied molecular orbital of the aromatic-hydrocarbon ring having same number of ( pi ) electrons, by 0.2 eV or more;    A1,A2=optionally substituted aromatic rings whose highest occupied molecular orbital is more than the highest occupied molecular orbital of the aromatic-hydrocarbon ring having same number of ( pi ) electrons, by 0.2 eV or more;    N1=optionally substituted aromatic rings whose highest occupied molecular orbital is less than the highest occupied molecular orbital of the aromatic-hydrocarbon ring having same number of ( pi ) electrons, by plus minus 0.2 eV;    p,q,r=1 or more;and    s=2-3.    The highest occupied molecular orbital levels are calculated by MP2/6-31Gasterisk by Gaussian03.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of solar cell containing organic photoelectric transducer of bulk interjunction type.    Organic photoelectric transducer (10)    Substrate (11)    Transparent electrode (12)    Counter electrode (13)    Photoelectric conversion portion (14)