A research team at Notre Dame University, with funding from the US Department of Energy, has developed the product called “Sun-Believable”, a kind of solar paint that when applied to non-conductive surfaces like glass or plastic can create electricity. The team had been researching new, less expensive ways in creating solar energy other than the more expensive silicon-based solar cells.
Researcher Matthew Genovese began the experiment by coating nanoparticles of titanium dioxide with nanocrystals of cadmium sulfide or cadmium selenide. The compounds absorb photons and when combined with a water-alcohol base create a semi-conductive yellow or brown paste. The team then applied the paste to a conductive glass surface electrode, connected it to a counter-conductive electrode, exposed it to sunlight, and was able to create a small current of energy.
Although there is a long way to go before making this a commercial product, the breakthrough is significant. The team has only achieved a light to energy conversion efficiency of 1%. A typical silicon-based solar cell achieves 10-15% efficiency. However the team feels if they can raise the efficiency of their solar cells to 4-5% the product can be used successfully. The paint is relatively cheap, can be made in any color, and doesn’t require a clean room to manufacture like the silicon cells.