Tin Could be a Potential Replacement for Silicon in Computers, Physicists Say

Stanene, a new material containing a thin layer of tin could potentially replace Silicon from the heart of transistors. A team of theoretical physicists said that a single layer of tin atoms can conduct electricity with 100 percent efficiency at room temperature.

Could this be the end of silicon's monopoly in electronic devices?

The word 'stanene' is derived from stannum (Latin name of tin) and the suffix of grapheme, another element with a promising future in electronics. Researchers say that using stanene could reduce power consumption and heat produced in microprocessors.

Shoucheng Zhang, a physics professor at Stanford and the Stanford Institute for Materials and Energy Sciences (SIMES), believes that we may have found a replacement for silicon.

For the past several years, Zhang and colleagues have been predicting electronic properties of a new class of materials called topological insulators. These materials act as insulators on the inside, but conduct electricity on their surfaces. Think of them as thick plastic cables with metal weaved around them, except that these insulators are made of a single material.

What's even exciting is that the conducting electrons arrange themselves as 'spin up' or 'spin down,' making them very useful in quantum computing.

When these topological insulators are just one atom thick, their edges conduct electricity with 100 percent efficiency.

Zhang and colleagues had earlier predicted that mercury telluride and several combinations of bismuth, antimony, selenium and tellurium could be good topological insulators and independent experiments supported their claims. However, none of these materials were 100 percent efficient at room temperature.

The team found their answer lying in a single layer of tin.

 "We knew we should be looking at elements in the lower-right portion of the periodic table," Yong Xu, who is now at Tsinghua University in Beijing and a collaborating scientist said in a news release. "All previous topological insulators have involved the heavy and electron-rich elements located there."

According to their calculations, a single layer of tin could be a good topological insulator at and above room temperature.  With fluorine atom, stanene could even work to 100 degrees Celsius or 212 degrees Fahrenheit.

Stanene-fluorine combination could be used in wiring that connects several sections of the microprocessor.

"Eventually, we can imagine stanene being used for many more circuit structures, including replacing silicon in the hearts of transistors," Zhang said in a news release. "Someday we might even call this area Tin Valley rather than Silicon Valley."

Zhang said that the team's predictions need to be verified by lab studies. 

The research team was led by U.S. Department of Energy's (DOE) SLAC National Accelerator Laboratory and Stanford University and their study is published in the journal Physical Review Letters.

For more information on Topological Insulators, check Charles Kane and Joel Moore's feature.