Electronic structure, photovoltaic and absorption properties of designed photo-efficient new organic dyes with D-π-A framework

In this study, a series of donor-π-acceptor systems were designed by introducing different π-bridges as functional groups. The geometric, electronic, quantum chemical, photovoltaic and absorption properties were investigated by the density functional theory (DFT) and time dependent-DFT method to approve which dyes show a good performance dye-sensitised solar cells. The six derivatives of organic D-π-A structures were studied, based on methyl substituted benzodithiophene as the donor group and ortho-fluorine-substituted phenyl, with cyanoacrylic acid as electron acceptor group with different π-bridges. The results expose that the introduction of the different π-bridge are more promising for formation of organic dyes with D-π-A arrangement. Also, the results found that the all dyes have better open circuit photovoltage, better light-harvesting efficiencies, higher electron injection efficiency and excellent photovoltaic efficiency. Therefore, these properties suggest that these new materials behave as better applicants and synthesis of photo-efficient dyes for sensitisers in DSSCs.