科學60秒:太陽能電池板? OUT啦!

Instead of installing solar panels on your roof — how about just giving your house a new paint job? Of course you'd have to be sure to use solar paint. That's what a group of Notre Dame researchers has created, detailing the recipe in the journal ACS Nano. The paint contains nanoparticles of titanium dioxide — which gives whiteness to sunscreen and powdered sugar. The particles are coated with semiconducting cadmium nanocrystals, and mixed with water and alcohol, to create a golden yellow paste. The researchers dubbed the product "Sunbelievable." They brushed it onto a conductive glass electrode, and attached that to a counter-electrode, to create a complete circuit. When they shined light on the tiny solar cell, it pumped out a small current. The efficiency of the light-to-electricity conversion was only about one percent — much lower than the 10 to 15 percent efficiency of conventional silicon cells. But the researchers say this paint is relatively cheap, can be made in any color, and doesn't require a clean room to manufacture, like silicon cells — just a bench top. If they can up the efficiency a bit, a future Tom Sawyer could make an electric fence.