Dye-sensitized solar cells (DSCs) convert sunlight to electricity. In the modern configuration of DSCs randomly packed interconnected dyecoated titanium dioxide nanoparticle (TiO2 NP) electrodes platinum-coated counter-electrodes and iodide/triiodide redox couple solutions are sandwiched together to form the cell. Benzoic acid is commonly used to anchor dye molecules to the TiO2 substrate. However the use of a single benzoic acid anchoring group to immobilize organic dyes on TiO2 nanoparticles provides the dyes with a high tendency to dissociate gradually from the TiO2 surface causing them to lose their capacity to convert photons to electrons and to reduce the solar cell’s long-term stability.
This invention addresses the poor long-term stability of dyesensitized solar cells by increasing the binding capacity of porphyrins to metal oxides. In addition the unique binding modes will enhance the electron injection for increased energy conversion efficiency. The result is a product with stronger binding capability to metal oxide semiconductors a broader adsorption and better injection efficiency.