IIT researchers develop method to enhance the efficiency of existing solar cells

Researchers at the Indian Institute of Technology Hyderabad have developed a new process that promises to improve the performance of Dye-Sensitized Solar Cells (DSSC). Dye-sensitized solar cells hold a lot of promise because of the possible cost and environmental benefits. But they have low light-to-power conversion efficiency. The new process promises to enhance efficiency. The first-generation silicon-based cells with energy harvesting efficiency of about 26 percent continue to be costly. Second-generation thin film solar cells based on semiconductors like cadmium-telluride and cadmium-selenide have comparable efficiencies, and not much lower cost. The third generation of dye-sensitized solar cells can significantly lower the costs of solar cells while being environment-friendly.

But, their efficiencies need improvement to translate to practical products. Researchers initially tried introducing holmium oxide, a powerful paramagnetic material, into the anode of the cell and by applying external magnetic fields. The experiment showed an enhancement in efficiency. However, the application of an external magnetic field can be power-consuming because electromagnets themselves require energy for their functioning. The team consequently replaced holmium oxide with iron oxide magnetic nanoparticles since it produced a magnetic field internally. The result was as good. “A dye molecule absorbs the light energy in DSSC and causes electrons in the dye to jump to titania and then to the external circuit, which causes a flow of electrons, leading to a current,” explained Dr Jammalamadaka Suryanarayana, who led the research team. Dr Suryanarayana conducted the study with his student U.M. Kannan and Dr L. Giribabu, senior scientist, Indian Institute of Chemical Technology, Hyderabad. The team has published a report on their work in the journal Solar Energy.