Study On The Physical Properties Of Polyene And Furan Dyes With Functional Group

As a novel renewable and clean solar energy conversion system, dye-sensitized solar cell (DSSC) has attracted extensive interest due to the high efficiency at low cost. D-π-A type organic chromophores are increasingly applied in DSSC by virtue of their high molar extinction coefficient, low cost, as well as their rich structures. However, the problems remain so far is that:First, the electronic part and the part of the dye molecules adsorbed groups are always difficult to separate, second, the absorption spectroscopy of the dye molecules always stay away from the near-infrared spectral region.Due to the diversity of polyene and furan dyes of organic molecular structure, the introduction of functional groups can make a change to the molecular structure which may play a role in regulating the photophysical properties of the dye molecules, making it theoretically more suitable as a photosensitizer for DSSC. This paper designed based on polyene dyes D5, D9and furans dye Fl, F2as well as types of its functional groups congeners. By simulation of DFT/TDDFT, we can get the conclusion of the adsorption spectrum,the geometric structure, and the energy level structure of the molecule, exploring changes of the photophysical properties of dye molecules after functional groups for polyene and furans have been used.Polyene and furan dyes are used in DSSC. Through introduction of functional groups in different locations of the dye molecules we design its congener molecules. Such as (-F,-CF3,-CN) belong to electron-accepting groups and (-NH2,-OH,-OCH3) belong to electron-donating groups.12kinds of novel organic dyes were designed and synthesized. By introduction of functional groups the HOMO, HOMO-1, LUMO, LUMO+1level of the dye molecule can get a change, which may be the key factor affecting the molar absorption coefficient and the absorption spectrum.The results of the photophysical properties of polyene and furan series dyes showed:by introducing appropriate functional groups on the molecular skeleton of such dyes, the absorption spectrum of the dye is broadened and get red shift while the light absorption capacity of the dye get a enhance. The red shift of the absorption spectrum of the dye can get the largest if the electron-donating group is introduced functional group of dual-OH while the acceptor groups introduced by electrophilic group of-CN.