2D or Not 2D Semi-Conductor Material

Researchers have successfully produced a 2D ultra-bandwidth semi-conductor material with the excellent electronic properties of graphene added to gallium nitride.

An illustration of the Migration Enhance Encapsulated Growth (MEEG) process to stabilize novel wide-bandgap two-dimensional nitride semiconductors that are not naturally occurring. MEEG is facilitated by defects in the graphene lattice that act as pathways for intercalation. When the gallium and nitrogen atoms meet at the graphene/SiC interface, they chemically react to form two-dimensional gallium nitride. (Z. Al Balushi and Stephen Weitzner / Penn State MatSE)

Semi-conductor materials enable devices to operate at high voltages and extremely high temperatures, useful in military radar, and lasers. The ultra-bandwidth versions promise advances in alternative energy technology and more efficient electric vehicles.

Applications in deep ultraviolet lasers, next-generation electronics and sensors are possible using what is claimed to be the first-ever growth of two-dimensional gallium nitride using graphene encapsulation with its attendant electronic properties.

Pennsylvania State scientists have been focusing on making 2D gallium nitride. Its three-dimensional form is recognised as a wide-bandgap semiconductor, important for high frequency, high power applications. In its two-dimensional form, gallium nitride transforms from a wide-bandgap to an ultra-wide-bandgap material, effectively tripling the energy spectrum in which it can operate including the whole ultraviolet, visible and infrared spectrum, having implications relating to electro-optic devices.

The graphene is grown on a substrate of silicon carbide – an advanced substrate. When heated, the silicon on the surface decomposes and leaves a carbon-rich surface that can reconstruct into graphene. The advantage of producing the graphene in this way is that the interface where the two materials meet is perfectly smooth.