Scientists discover first P-type 2D semiconductor

University of Utah engineers have discovered a new kind of two-dimensional (2D) semiconducting material for electronics that opens the door for much speedier computers and smartphones that also consume a lot less power. The semiconducting material comprises a one-atom-thick layer of tin monoxide (SnO), through which electrical charges can move much faster than conventional three-dimensional (3D) materials such as silicon.

The material was discovered by a team led by University of Utah materials science and engineering associate professor Ashutosh Tiwari. A paper describing the research appears in Advanced Electronic Materials; it was co-authored by University of Utah materials science and engineering doctoral students K. J. Saji and Kun Tian, and Michael Snure of the Wright-Patterson Air Force Research Lab near Dayton, Ohio, US.

The transistors that form basis of all computer processors, together with many other components of computer chips, are currently made from multiple layers of materials like silicon on a glass substrate. The downside to such 3D materials is that electrons bounce around inside the layers in all directions.

The benefit of 2D materials, which is an exciting new research field that has opened up over the past five years, is that they are made of a single layer with a thickness of just one or two atoms. Consequently, the electrons "can only move in one layer so it's much faster," explains Tiwari.

While researchers in this field have recently discovered new types of 2D material such as graphene, molybdenum disulfide and borophene, these materials only allow the movement of negative electrons, making them N-type semiconductors. In order to create a transistor, however, you need both N-type semiconductors and P-type semiconductors, which allow the movement of positive charges known as ‘holes’. The tin monoxide material is the first stable P-type 2D semiconductor ever discovered.

"Now we have everything – we have P-type 2D semiconductors and N-type 2D semiconductors," says Tiwari. "Now things will move forward much more quickly."

Now that Tiwari and his team have discovered this new 2D material, it can lead to the manufacture of transistors that are even smaller and faster than those in use today. A computer processor is comprised of billions of transistors, and the more transistors that can be packed into a single chip, the more powerful the processor can become.

Transistors made with Tiwari's semiconducting material could lead to computers and smartphones that are more than 100 times faster than current devices. And because the electrons move through one layer instead of bouncing around in a 3D material, there will be less friction, meaning the processors will not get as hot as normal computer chips. They also will require much less power to run, a boon for mobile electronics that have to run on battery power. Tiwari says this could be especially important for medical devices such as electronic implants, which will be able to run longer on a single battery charge.

"The field is very hot right now, and people are very interested in it," Tiwari says. "So in two or three years we should see at least some prototype device."

This story is adapted from material from the University of Utah, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.