Synthesis, Properties Of Phenanthroline Derivatives Containing Thiophenyl

With the depletion of non-renewable resources, the use of sunlight has been paid much attention. Organic solar cells have been widely applied due to its simple preparation, light weight, low cost and large flexible area. One of the limiting parameters for power conversion efficiencies(PCEs) of organic solar cells is the mismatch between the absorption spectrum of the photoactive layer and the terrestrial solar radiation, which leads to only a small portion of solar energy being utilized. A series of D-A molecules, containing 1,10-phenanthroline group as electron donor and thiophene, thienylenevinylene as electron acceptor based on thiophene and 1,10-phenanthroline were synthesized. These compounds have a broad absorption band and low band gap, getting potentials advantages as photovoltaic material. We researched the following aspects in this paper:(1) The 1,10-phenanthroline derivatives modified by thienyl and thienylenevinylenyl groups at 3-and 3,8-position were designed and synthesized. The structures of these donor-acceptor compounds TPh,DTPh, OTETPh, DOTETPh, DOTETTPh were characterized by 1HNMR and IR.(2) The photophysical properties of products were measured by ultraviolet-visible absorption spectrum and emission spectrum. The results showed that compounds have a broad absorption band and low band gap, getting potentials advantages as photovoltaic material. Then the UV-vis spectra and the fluorescence emission spectrum of products were tested at different concentrations in chloroform. We observed that the absorption intensity have added with the increasing concentration and solvent effects lead to redshift of maximum absorption peak and maximum emission peak of compounds with the increase of solvent polarity.(3) DSC showed that compounds have good thermal stability.(4) XRD found that compounds have clear crystal phase in solid state instead of amorphous structure.