Synthesis Of Triarylmethane Derivatives And Their Photoelectrochemical Properties For Dye Sensitized Solar Cell

Among the solar cell, Dye Sensitized Solar Cell (DSSC) has broad prospects of application. Dye is one of the main part of this kind of cell. Considering that metal-free organic dyes have the advantages of cheap raw materials, easy tailoring of molecular and no pollution to environment, we developed organic dyes consisting of a triarylmethane unit firstly because triarylmethanes have the similar structure with triphenylamine. In addition, we investigated the photovoltaic performances of these dyes. Furthermore, we drew disciplinary conclusions.(1) We designed and synthesized four new organic dyes named TTM-1、TTM-2、TTM-3and TTM-4. The connections between structure and properties of four dyes TTM-1-TTM-4have been analyzed. It was verified that oxidation potentials of the ground and exited state for the four dyes, which are usually replaced by HOMO and LUMO, match with the energy level of I-/I3-redox potential and ECB of the TiO2electrode by cyclic voltammetry, respectively. The result shows high molar extinction coefficients and their maximum absorption exhibit rules which indicate that hexyl substituted thiophene in donor moiety make no difference to the absorption and dyes with extra thiophene in%moiety are red-shifted. More delocalization over a conjugated system can be proved by the dihedral angle (0.1°,3.5°,22°to TTM-2-TTM-4) optimized structure analyzed by using the Gaussian09program package.(2) The photoelectrochemical properties of four new dyes have been studied in DSSC. The responding range of IPCE curve is consistent with the UV-visible absorption spectra, while TTM-3has a broad respond range among the four DSSCs and the IPCE reached34%. Additionally, conversion efficiencies of all the cell devices are0.1%、0.32%、0.56%and0.26%, respectively. This influence factors of photoelectric properties were analyzed and discussed in the article as well as the ways to improve the conversion efficiencies.