If you've always dreamed of having infrared vision like a superhero, your wish could soon come true as engineering researchers at the University of Michigan have invented the world's first room-temperature light detector that can see infrared light.
The researchers have invented a new detector the size of a fingernail that they say can be integrated with contact lenses or a mobile phone.
Infrared light is tricky to see as it requires a combination of technologies that are able to detect near-, mid- and far-infrared radiation all at once. Usually, mid- and far-infrared sensors have be at very cold temperatures.
Graphene would be a possible option as it consists of a single layer of carbon atoms that can sense the whole infrared spectrum, but until now, the material hasn't been able to capture enough light to generate an electrical signal so that it can sense it.
"The challenge for the current generation of graphene-based detectors is that their sensitivity is typically very poor. It's a hundred to a thousand times lower than what a commercial device would require," said Zhaohui Zhong, assistant professor of electrical and computer engineering at the University of Michigan.
To solve the challenge, Zhong and his colleagues have designed a new detector that places an insulating barrier layer between two graphene sheets. When light hits the top sheet, electrons are freed which create positively-charged holes.
The electrons then slip through the barrier layer onto the bottom layer of graphene and produce an electric field which effects the flow of electricity and enables the light to be detected.
"Our work pioneered a new way to detect light. We envision that people will be able to adopt this same mechanism in other material and device platforms," said Zhong.
"If we integrate it with a contact lens or other wearable electronics, it expands your vision. It provides you another way of interacting with your environment."
The University of Michigan researchers' work appears in a study entitled "Graphene photodetectors with ultra-broadband and high responsivity at room temperature" in the Nature Nanotechnology online journal.