Scientists find 'greener' recipe for photovoltaics

Zinc oxide could provide a more environmentally friendly way to produce photoconducting materials and photovoltaics, according to researchers at Northwestern University.

The best photoconductors today are made with toxic lead sulfide nanoparticles, making them less green than they could be.

Unlike lead sulfide, zinc oxide is a benign inorganic compound used in products like sunscreen and baby powder. Zinc oxide also offers the benefits of low-cost production, a high ability to detect light and convert it to energy, mechanical flexibility and the ability to “tune” photoconducting materials to absorb a preferred range of the solar spectrum.

“One property of our hybrid material that is especially important for solar-energy devices is its high level of detectivity — less light is needed to get a good strong and clear signal,” said lead researcher Samuel I. Stupp. “This comes from the material’s highly ordered architecture, which helps transport the electrons efficiently.”