One of the most prestigious grants offered by the NSF, CAREER awards are designed to help junior-level faculty build their research programs and establish a track record of successful investigations. Bao’s grant, for $400,000 over five years, will allow him to examine the optical properties of graphene, one-atom-thick sheets of carbon.
Electromagnetic wave simulations have shown that graphene has the ability to act as an optical waveguide for surface plasmon, essentially serving as a pathway along which these electromagnetic waves can travel.
This property has not been well established through real world experimentation, however. By creating sheets of graphene and then etching nano-scale features into the material, Bao aims to confirm its ability to conduct surface plasmon and characterize how well different types of graphene nanoribbons perform this task.
If Bao is able create and observe graphene with good optical waveguide properties, nanoribbons of the material could serve as optical interconnects in electronic devices, improving computing speed.
“If you want to send a message from one transistor to another, right now you have to use copper wire,” said Bao. “That’s a low frequency electrical signal. Surface plasmon has a higher frequency. So the bandwidth will increase a lot, making the information transmission rate much higher than copper.”
What’s more, establishing the plasmon-related properties of the material could allow researchers to use it for molecular sensing, said Bao. By creating graphene nanodisks with strong localized surface plasmon resonances and attaching them to molecules, changes in how the plasmon behaves on these particles would signal that molecular bonding has occurred.
While all this is promising, Bao stressed that utilizing graphene in these ways is dependent upon him achieving his first goal: confirming the ability of graphene to confine surface plasmon. “You need to first demonstrate surface plasmon on graphene and observe its optical properties. You can see it in simulations, but you must find ways to observe it in the lab,” he said.