NOVELTY - A liquid crystal molecule comprises a gallic-acid derivative portion (I), a fullerene-acid derivative portion and a flexible connecting arm. The precursor of flexible connecting arm is diol (II). The ends of flexible connecting arm are connected to gallic-acid derivative portion and fullerene-acid derivative portion by an ester bond. The hydroxyl group is removed from gallic acid to form gallic-acid derivative portion, and the hydroxyl group is removed from the fullerene acid to form fullerene-acid derivative portion through the formation of ester bond.    USE - Liquid crystal molecule is used as receptor material for preparing heterojunction solar cell (claimed).    ADVANTAGE - The liquid crystal molecule has high fullerene content and low phase-transition temperature. Highly efficient solar cell is prepared easily using the liquid crystal molecule.    DETAILED DESCRIPTION - A liquid crystal molecule comprises a gallic-acid derivative portion of formula (I), a fullerene-acid derivative portion and a flexible connecting arm. The precursor of flexible connecting arm is diol of formula: HO-R1-OH (II). The ends of flexible connecting arm are connected to gallic-acid derivative portion and fullerene-acid derivative portion by an ester bond. The precursor of gallic acid derivative portion is gallic acid derivative. The hydroxyl group is removed from gallic acid to form gallic-acid derivative portion through the formation of ester bond. The hydroxyl group is removed from the fullerene acid to form fullerene-acid derivative portion through the formation of ester bond. The fullerene-acid derivative is 60C fullerene acetate, 60C fullerene propionate or 60C fullerene malonate.    R=CnH2n+1 alkyl;    n=1-21;    R1=CmH2m;and    m=2-12.    An INDEPENDENT CLAIM is included for preparation of heterojunction solar cell. An electron blocking layer is arranged on a clear conductive glass. A conjugated polymer or conjugated organic micromolecules as donor material is mixed with high fullerene liquid crystal molecule as receptor material. The resultant mixed solution is spin-coated on the electron blocking layer at normal temperature, to form an active film. A layer of electrode is arranged on the active film, to obtain organic polymer heterojunction solar cell.