As the installation of photovoltaic solar cells continues to accelerate, scientists are looking for inexpensive materials beyond the traditional silicon that can efficiently convert sunlight into electricity.
Theoretically, iron pyrite — a cheap compound that makes a common mineral known as fool’s gold — could do the job, but when it works at all, the conversion efficiency remains frustratingly low. Now, a University of Wisconsin–Madison research team explains why that is, in a discovery that suggests how improvements in this promising material could lead to inexpensive yet efficient solar cells.
“We think we now understand why pyrite hasn’t worked,” says chemistry Professor Song Jin, “and that provides the hope, based on our understanding, for figuring out how to make it work. This could be even more difficult, but exciting and rewarding.”
Although most commercial photovoltaic cells nowadays are based on silicon, the light-collecting film must be relatively thick and pure, which makes the production process costly and energy-intensive, says Jin.