Dye-sensitized solar cells use a special dye sandwiched between two semiconductors to convert sunlight into electricity. The technology is promising for low-cost, large-scale electricity generation due to its simple construction from common paint pigments and absorbing molecules. Optimization of these devices over the past two decades has led to efficiencies of greater than 10%, yet further advances are needed before large-scale adoption will occur.
To make the process more efficient, the researchers propose synthesizing new dyes that will do a better job of keeping the negative charge carriers in one semiconductor away from the positive charge carriers in the other semiconductor. They expect to generate more current and achieve a higher voltage. Efficiencies can be raised if the interface between the titanium dioxide electrode and the electrolyte solution is controlled. Their proposed two-step dye attachment strategy contains a blocking layer of molecules on the electrode. This foundational layer will reduce the short-circuiting of the solar cell allowing the redox mediators, which assist in transferring electrons, to be altered to increase the operating voltage and attendant efficiency of the device. Over the past six months, they have synthesized the majority of the component molecules needed to assemble their first dye-sensitized solar cell.