A team of researchers from the University of Notre Dame in Indiana has created a material called "solar paint" that they say could pave the way for cheaper solar cell technology.

Solar panels aren't cheap to produce but with the new discovery by the Notre Dame scientists, cheap and mass-produced solar cells could soon be in our future. The material called "Sun-Believable" is made from quantum dot particles. The team coated nanoparticles of titanium dioxide with cadmium sulfide or cadmium selenide. Both compounds can easily absorb photons. When a photon hits the cadmium compounds, an electron escapes and is absorbed by the titanium dioxide.

The team then suspended the compound in a water-alcohol mixture to create a paste. The cadmium sulfide mixture produced a yellow paste while the other cadmium mixture produced a dark brown paste. The team found that a combination of the two pastes created the most efficient compound at releasing energy.

Brushing the paste on a transparent conducting material and exposing it to light creates electricity. Cathodes made from other materials and additional compounds were used to replenish the electrons lost by the cadmium compounds.

"The best light-to-energy conversion efficiency we've reached so far is 1 percent, which is well behind the usual 10 to 15 percent efficiency of commercial silicon solar cells," said Prashant Kamat, an investigator in Notre Dame's Center for Nano Science and Technology (NDnano). "But this paint can be made cheaply and in large quantities. If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future."

Kamat and his team plan to develop the paint's conversion efficiency and improve its stability. Although the efficiency of the paint is below the efficiency of silicon-based solar panels, Kamat believes the paint could be further improved and that Sun-Believable could "make a real difference in meeting energy needs in the future."

The Notre Dame team's findings are published in the journal ACS Nano.