NOVELTY - A photoelectric conversion element has active layer containing high molecular compound having cyclic structural unit (I) provided between electrodes. The inverse excitation energy for shift from singlet ground state to lowest excited singlet state of the high molecular compound is more than 0.43 eV-1.    USE - Photoelectric conversion element for solar cell module and image sensor (both claimed).    ADVANTAGE - The photoelectric conversion element has high short-circuit current density and high photoelectric conversion efficiency.    DETAILED DESCRIPTION - A photoelectric conversion element has active layer containing high molecular compound having cyclic structural unit of formula (I) provided between electrodes. The inverse excitation energy for shift from singlet ground state to lowest excited singlet state of the high molecular compound is more than 0.43 eV-1.    Ar1,Ar2=trivalent aromatic hydrocarbyl or trivalent heterocyclyl;    X1,X2=-O-, -S-, -C(=O)-, -S(=O)-, -SO2-, -C(R50)(R51)-, -Si(R3)(R4)-, -N(R5)-, -B(R6)-, -P(R7)- or P(=O)(R8)-;and    R50,R51,R3-R8=H, halo or monovalent organic group chosen from alkyl, alkyloxy, alkylthio, aryl, aryloxy, arylthio, arylalkyl, arylalkyloxy, aryl alkylthio, acyl, acyloxy, amide, acid-imide, optionally substituted amino, substituted silyl, substituted silyloxy, substituted silylthio, substituted silylamino, monovalent heterocyclyl, heterocyclyl oxy, heterocyclyl thio, aryl alkenyl, aryl alkynyl, carboxy, or cyano.    X1 and Ar2 are bonded with the atom adjacent in the ring containing Ar1, and X2 and Ar1 are bonded with the atom adjacent in the ring containing Ar2. INDEPENDENT CLAIMS are included for the following:    (1) organic transistor thin film, which consists of active layer containing the high molecular compound provided between electrodes; and    (2) calculation of excitation energy of the high molecular compound having repeating unit, which involves calculating the excitation energy of aryl compounds of formulae: H-Ar3-H, H-Ar3-Ar3H and H-(Ar3)3-H.    Ar3=divalent organic group.