The Ohio State team has discovered a way to simplify how electronic devices use those electrons through a single material that can serve dual roles in electronics, where historically multiple materials have been necessary.
"We have essentially found a dual-personality material," said Joseph Heremans, co-author of the study and a professor at Ohio State. "It's a concept that didn't exist before."
Their findings could mean a revamp of the way engineers create all different kinds of electronic devices. This includes everything from solar cells, to the light-emitting diodes in your television, to the transistors in your laptop, and to the light sensors in your smartphone camera.
Those devices are the building blocks of electricity: each electron has a negative charge and can radiate or absorb energy depending on how it is manipulated. Holes - essentially, the absence of an electron - have a positive charge. Electronic devices work by moving electrons and holes - conducting electricity.
But, historically, each part of the electronic device could only act as electron-holder or a hole-holder, not both. That meant that electronics needed multiple layers and multiple materials to perform.
But the Ohio State researchers found a material - NaSn2As2, a crystal that can be both electron-holder and hole-holder, potentially eliminating the need for multiple layers.
"Now, we have this new family of layered crystals where the carriers behave like electrons when traveling within each layer, and holes when traveling through the layers," said Joshua Goldberger, associate professor of chemistry and biochemistry at Ohio State.
"You can imagine there might be some unique electronic devices you could create..."
The researchers named this dual-ability phenomenon "goniopolarity." They believe the material functions this way because of its unique electronic structure, and say it is probable that other layered materials could exhibit this property.
"We just haven't found them yet," Prof Heremans said. "But now we know to search for them."
The researchers made the discovery almost by accident. A graduate student researcher in Prof Heremans' lab, Bin He, was measuring the properties of the crystal when he noticed that the material behaved sometimes like an electron-holder and sometimes like a hole-holder – something that, at that point, science thought was impossible.
He thought perhaps he had made an error, ran the experiment again and again, and got the same result.
