The research team that announced the first optical rectenna in 2015 is now reporting a two-fold efficiency improvement in the devices — and a switch to air-stable diode materials. The improvements could allow the rectennas – which convert electromagnetic fields at optical frequencies directly to electrical current – to operate low-power devices such as temperature sensors.
Ultimately, the researchers believe their device design – a combination of a carbon nanotube antenna and diode rectifier – could compete with conventional photovoltaic technologies for producing electricity from sunlight and other sources. The same technology used in the rectennas could also directly convert thermal energy to electricity.
“This work takes a significant leap forward in both fundamental understanding and practical efficiency for the optical rectenna device,” said Baratunde Cola, an associate professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “It opens up this technology to many more researchers who can join forces with us to advance the optical rectenna technology to help power a range of applications, including space flight.”