Synthesis And Study Of Several Heteroanthracene Sensitized Dyes In Dye-Sensitized Solar Cells

Photosensitizer is the key component for the dye sensitized solar cells (DSSCs), which leading excited state electrons injection into the conduction band of the TiO2under the irradiation of sunlight. At the same time, the dye is quickly regenerated by the electrolyte(l3-/I-). In order to reduce the cost of the dye sensitized solar cells, the organic sensitizers have developed rapidly in recent years compared with the noble metal complex sensitizers.In this thesis, nine aromatic organic dyes have been designed and synthesized as the sensitizers for the dye sensitized solar cells, which containing seven heteroan thracene sensitizers and two triphenylamine sensitizers. The structures of the dyes have been characterized by1HNMR and13CNMR technology. At the same time, we study the electrochemical and photophysical properties of the DSSCs.The photophysical properties of sensitizers is closely linked to its structure. The experiments show that the photophysical properties of sensitizers is significantly affected by its conjugacy. The more steric hindrance, the worse its conjugacy, which impedes transfer of electrons in the dye molecule and lead to the decrease of the ability to absorbing sunlight. For the dyes, the introduction of electron-withdrawing units to π-conjugation spacer can achieve red-shifted of absorption spectra. LUMO and HOMO levels of sensitizers match well with the I3-/I-and the TiO2conduction band respectively. The structure of sensitizers have a crucial effect on the HOMO and LUMO level of the dyes. Introduction of DTT unit as π-conjugation spacer moieties will increased value of the HOMO level, so that the electrolyte I3-/I-electrical potential difference between a pair of smaller, which resulting in reduction the driving force regeneration of the dyes.The structure of sensitizers have a important effect on the photovoltaic properties of the dyes. The study of various electron donor on triphenyl amine and anthracene show that The electron donor is non-planar configuration of the photosensitive dye can effectively prevent the surface of the titanium dioxide H-aggregation and obtain a higher photoelectric conversion efficiency in the absence of the molecule aggregation inhibitor.