A novel fabrication technique developed by a University of Connecticut engineering professor could provide the breakthrough technology scientists have been looking for to vastly improve the efficiency of today's solar energy systems.
For years, scientists have studied the potential benefits of a new branch of solar energy technology that relies on nanosized antenna arrays theoretically capable of harvesting more than 70 percent of the sun's electromagnetic radiation and simultaneously converting it into usable electric power.
But while nanosized antennas that also serve as rectifiers have shown promise in theory, scientists have lacked the technology required to construct and test them. The fabrication process is immensely challenging. The nano-antennas known as "rectennas" because of their ability to both absorb and rectify solar energy from alternating current to direct current must be capable of operating at the speed of visible light and be built in such a way that their core pair of electrodes is a mere 1 or 2 nanometers apart, a distance of approximately one millionth of a millimeter, or 30,000 times smaller than the diameter of human hair.
The potential breakthrough lies in a novel fabrication process called selective area atomic layer deposition (ALD) that was developed by Brian Willis, an associate professor of chemical and biomolecular engineering at the University of Connecticut and the former director of UConn's Chemical Engineering Program.
It is through atomic layer deposition that scientists believe they can finally fabricate a working rectenna device. In a rectenna device, one of the two interior electrodes must have a sharp tip, similar to the point of a triangle. The secret is getting the tip of that electrode within one or two nanometers of the opposite electrode, something similar to holding the point of a needle to the plane of a wall. Before the advent of ALD, existing lithographic fabrication tech
|Contact: Colin Poitras|
University of Connecticut