Silicon alternatives key to future computers, consumer electronics

Researchers are reporting key milestones in developing new semiconductors to potentially replace silicon in future computer chips and for applications in flexible electronics. 

Findings are detailed in three technical papers, including one focusing on a collaboration of researchers from Purdue University, Intel Corp. and SEMATECH, a consortium dedicated to advancing chip manufacturing. The team has demonstrated the potential promise of an extremely thin - or "two-dimensional" - semiconductor called molybdenum disulfide.

Although molybdenum disulfide has been studied by research groups around the world, a key obstacle to its practical use has been a large electrical resistance between metal contacts and single-atomic layers of the material. This "contact resistance" limits the flow of current between the contacts and the molybdenum disulfide, hindering performance.

"This is a fundamental bottleneck," said Peide "Peter" Ye, a Purdue professor of electrical and computer engineering.
Now, researchers have shown how to overcome this obstacle by "doping" the material with the chemical compound 1,2 dichloroethane (DCE), meaning single layers of molybdenum disulfide are impregnated with the DCE. This doping results in a 10-fold reduction of contact resistance and a 100-fold reduction of contact resistivity, another measure of resistance.

The findings are fundamental to learning how to develop alternatives to silicon that will likely be needed after 2020, when, it is thought, silicon transistors will reach their technological limits, stalling further progress.