Introduction of new configuration of dyes contain indigo group for dye-sensitized solar cells: DFT and photovoltaic study

Abstract

The chemical structure engineering of photosensitizers has a major role in photovoltaic devices such as dye-sensitized solar cells. Thus, a novel dye system was designed and prepared with contained indigo group for increasing light resistance as well as cyanoacrylic acid for improving the interaction. All intermediates and dyes were purified and analyzed using FTIR, HNMR, CHN and UV–Visible. The results showed that all the expected dye chemical structures have been achieved. Two semiconductors namely titanium dioxide and Na-doped titanium dioxide, were coated with the synthesized dye to prepare photoanode. All prepared samples illustrated blue shift in UV–Visible due to H-aggregation of dyes on the semiconductor. The energy level of dyes was investigated by Cyclic Voltammetry technique and DFT calculation. The results confirmed the possibility of using dyes in the structure of dye-sensitized solar cells. All prepared dyes were utilized as photosensitizers in dye-sensitized solar cells. The efficiency of Dye 6 in dye-sensitized solar cells based on titanium dioxide and its Na-doped derivative was 7.17% and 7.56%, respectively. Optical devices based on Na-doped semiconductor showed superior performance to those based on pristine titanium dioxide.