NOVELTY - Dye sensitized photoelectric conversion element comprises: a pair of electrodes arranged opposite to each other, a semiconductor layer including a semiconductor (3) supporting a sensitizing dye (4); and an electrolyte layer, where the semiconductor layer and the electrolyte layer are provided between the pair of electrodes, and the sensitizing dye contains 3,5-dihydro-imidazol-4-one compounds (I).    USE - The dye sensitized photoelectric conversion element is useful in a solar cell (claimed).    ADVANTAGE - (I) is good at adsorbing to an oxide semiconductor, and has high photoelectric conversion efficiency.    DETAILED DESCRIPTION - Dye sensitized photoelectric conversion element comprises: a pair of electrodes arranged opposite to each other, a semiconductor layer including a semiconductor (3) supporting a sensitizing dye (4); and an electrolyte layer, where the semiconductor layer and the electrolyte layer are provided between the pair of electrodes, and the sensitizing dye contains 3,5-dihydro-imidazol-4-one compounds of formula (I).    Ar1 = arylene or heterocyclic group (both optionally substituted);    R1 = alkyl, alkenyl, alkynyl, aryl or heterocyclic group (all optionally substituted), where R1 and Ar1 may form a ring-shaped structure by bonding with each other;    R2 = alkyl, alkenyl, alkynyl, alkoxy, aryl, amino or heterocyclic group (all optionally substituted), H, halo or cyano;    R3 = alkyl, alkenyl, alkynyl, aryl or heterocyclic group (all optionally substituted) or H;    R4 = alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylseleno, amino, aryl or heterocyclic group (all optionally substituted by X), where R4 is optionally further substituted with a substituent other than X;    X = acidic group;    n = 1 or more; and    m = 2 or 3, where the carbon-carbon double bond may be a cis form or a trans form.    An INDEPENDENT CLAIM is included for a solar cell comprising the photoelectric conversion element and a pair of terminals connected to the pair of electrodes.    DESCRIPTION OF DRAWING(S) - The figure shows a cross-sectional view of a photoelectric conversion element.    Substrates (1,1')    Transparent conducting layers (2, 7)    Semiconductors (3)    Sensitizing dyes (4)    Charge transport layer. (5)