NOVELTY - A photoelectric conversion element consists of a photoelectric conversion layer (E) containing a conductive polymer and an electron acceptor containing a fulleropyrrolidine derivative (I or II), provided between two electrodes (Y) formed on a substrate (T).    USE - Photoelectric conversion element e.g. tandem type solar cell element and photosensor element (both claimed). Can also be used for color sensors and other electronic device.    ADVANTAGE - The photoelectric conversion element has excellent photoelectric conversion efficiency.    DETAILED DESCRIPTION - A photoelectric conversion element consists of a photoelectric conversion layer containing a conductive polymer and an electron acceptor containing a fulleropyrrolidine derivative of formula (I or II), provided between two electrodes formed on a substrate.    R1 = -R8-C(=O)-O-R9, -R8-O-C(=O)-R9, -C(=O)-O-R10, -R8-C(=O)-NH-R9, -R8-NH-C(=O)-R9, -C(=O)-NH-R10, -R8-N(-R9)-R10, -(-R11-S-)a-(-R12-S-)b-R13;    R2=6-16C organic group having aromatic ring;    fullerene=60C, 70C, 76C or 84C fullerene;    R8 = group chosen from 1-16C linear or branched aliphatic hydrocarbyl and aliphatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom, 6-16C bivalent aromatic hydrocarbyl and aromatic (semi) perfluoro hydrocarbyl in which portion or all hydrogen atoms are substituted with fluorine atom;    R10 = group chosen from 1-16C linear or branched monovalent aliphatic hydrocarbyl and aliphatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom, and 6-16C monovalent aromatic hydrocarbyl and aromatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom;    R9 = H, 1-16C linear or branched monovalent aliphatic hydrocarbyl and aliphatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom, and 6-16C monovalent aromatic hydrocarbyl and aromatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom;    R11, R12 = 2-4C linear or branched bivalent aliphatic hydrocarbyl or aliphatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom;    R13 = H, 2-4C linear or branched monovalent aliphatic hydrocarbyl or aliphatic (semi) perfluoro hydrocarbyl in which portion of or all hydrogen atoms are substituted with fluorine atom;    a = 1-3; and    b = 0-3.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic sectional view of the photoelectric conversion element.    Photoelectric conversion layer (E)    Substrate (T)    Electrodes (Y)    Hole extraction layer (i-1)    Electron extraction layer (i-2)