NOVELTY - A bulk heterojunction-type organic photoelectric conversion element (10) has a transparent electrode (12), a counter electrode (13) and a photoelectric converting layer (14) containing p-type-semiconductor material and n-type-semiconductor material. The photoelectric converting layer contains condensed polycyclic aromatic compounds (IA-IC).    USE - Bulk heterojunction-type organic photoelectric conversion element for use in a solar cell and an optical sensor array (all claimed).    ADVANTAGE - The photoelectric conversion element has better heat resistance, and high photoelectric conversion efficiency, transparency, light absorbency, carrier mobility and durability.    DETAILED DESCRIPTION - A bulk heterojunction-type organic photoelectric conversion element has a transparent electrode, a counter electrode and a photoelectric converting layer containing p-type-semiconductor material and n-type-semiconductor material. The photoelectric converting layer contains condensed polycyclic aromatic compounds of formulae (IA-IC).    X1-X3=C or N (both optionally substituted), where one of X1,X2 is N;    Y1=chalcogen atom, preferably O;    R1-R7=H, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, amino, alkoxy, cycloalkyloxy, aryloxy, acyl, alkoxycarbonyl, aryloxy carbonyl, acyloxy, acylamino group, alkoxy carbonylamino group, aryloxy carbonylamino group, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, arylthio, sulfonyl, sulfinyl, ureido, amide phosphate (all optionally substituted), OH, mercapto group, halo, CN, sulfo group, carboxyl, NO2, hydroxamic acid, sulfino group, hydrazino group, imino group or heteroaryl group, where R1-R4 is =O, =S, =N-R8 or =CR9R10;    R8-R10=R1-R7.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a solar cell including a bulk heterojunction-type organic photoelectric conversion element.    Bulk heterojunction-type organic photoelectric conversion element (10)    Substrate (11)    Transparent electrode (12)    Counter electrode (13)    Photoelectric converting layer (14)    Positive hole transport layer (17)    Electron carrying layer (18)