While current solar energy technology, which is usually based on semiconductor technology made of silicon or gallium oxide functions at 20 percent efficiency on the high end, a University of Connecticut professor is working on a new technology that could harvest 70 percent of the sun’s electromagnetic radiation.
The technology uses nanosized antennas. Working with elements and distances as much as 30,000 times smaller than the diameter of a human hair, UConn engineering professor Brian Willis aims to build a prototype nano-antenna device that will both produce electric energy and harvest it.
“There’s no silicon or gallium oxide involved,” Willis said. “We have tiny electric waves on these metallic nanostructures.”
Willis said the metals need to be to be gold, silver or copper for conductivity. When you shine a light on the metallic nanostructures, they can shape that light and transform it into electric waves, Willis said.
Scientists have been researching this technology for years and it has advanced dramatically.
“What’s new about what we’re doing is that we’re trying to capture those electric waves and extract them,” Willis said.
The trick is to trap the energy. Willis has worked with partners at Penn State University on the theory. Together they have come up with a proof of concept that works. It concentrates the energy on the “tiny, tiny tip” of a nano-antenna. The next step is to extract it, which involves a flat surface placed just 1 or 2 nanometers away from the tip. It’s a lot like a static charge going from the head of a straight pin to a flat surface.
Willis has developed a fabrication process that he said should allow his team to develop a device that will both generate and capture electric energy. Using the selective area atomic layer deposition method Willis developed, the team has already created some proof of concepts. The next step is to build a prototype of the device.
“It won’t be tomorrow,” Willis said. “But it’s a single-digit number.”