A new family of 2D semiconductors could pave the way for high-performance and energy-efficient electronics. The findings may lead to the fabrication of semiconductor devices applicable in mainstream electronics and optoelectronics – and even potentially replace silicon-based device technology altogether.
2D semiconductors are materials with a thickness of a few atoms. Due to their nanoscale size, these materials are strong contenders as silicon substitutes in developing tiny electronic devices. When they contact metals, however, many such currently available semiconductors have significant electrical resistance.
The researchers showed that a recently discovered family of 2D semiconductors, namely MoSi2N4 and WSi2N4, form Ohmic contacts (metal-semiconductor contacts with no Schottky barrier) with the metals titanium, scandium, and nickel, widely used in the semiconductor device industry. An inert Si-N outer layer (that shields the underlying semiconducting layer from defects and material interactions at the contact interface) protects these materials from Fermi level pinning (FLP). This problem severely limits the application potential of other similar semiconductors.