You’ve heard the statistic: enough solar power hits the Earth in an hour to meet our energy needs for an entire year. The trick is harnessing it. Today’s solar cells make use of just under a third of the energy hitting them, overheating to create “hot electrons” that escape before they can be converted into electricity. A study published in this week’s Science demonstrates a new type of solar technology could harness quantum dots to convert two-thirds of the sun’s energy into electrical power.
The technology utilizes semiconductor nanocrystals, or “quantum dots” — which slow the cooling of hot electrons to create time to grab them — and a titanium dioxide conductor to accomplish the task. A previous study pioneered the use of quantum dots to slow the electrons’ cooling. The recently documented breakthrough is significant for its use of an inexpensive titanium dioxide “wire.”
Besides taking the discovery from theoretical science into practical engineering, one big problem still remains: hot electrons also lose their energy as they travel along the wire.
+ University of Minnesota
+ University of Texas
Via Science Daily