The performance of future electronic devices using nanotechnologies is set to improve thanks to a new and better process for synthesizing Hexagonal Boron Nitride (h-BN), an ultra-thin insulator used with wonder-nanomaterial graphene1.
Graphene is only one or two atoms thick, while also being very strong, and a heat and electricity conductor. It shows promise in creating everything from paper-thin television screens to bullet proof vests, but needs an insulating layer so that it can be held while electrically charged.
The compound h-BN is the world’s thinnest insulator and it has an atomically smooth surface devoid of charged impurities. This surface makes it an ideal material to support a layer of graphene, which requires an impurity-free and ultra-smooth interface.
The scientists Vikas Berry (left) and Sanjay Behura 
Currently, a h-BN film is produced on top of a metallic layer (like copper, nickel, cobalt or iron) and then transferred onto silicon-based layers. "These transfer steps consistently degrade h-BN’s structure via formation of tears, folds, wrinkles, and adsorption of polymeric or metallic impurities," Behura and Berry told Nature India .
The researchers and their colleagues at technology company SunEdison Semiconductor have leveraged surface chemical interactions of h-BN precursors to form large-area, thin films of h-BN directly onto silicon-based layers, eliminating the defect-creating first step.
They also created large-area ‘heterostructures’, or layered structures, of h-BN with graphene via an all ‘chemical-vapor-deposition’ approach. The researchers found this exhibited 3.5-fold enhancement in charge carrier mobility – the speed at which a charge like electricity moves through the material in a given direction – compared to graphene on silicon-based gate dielectric field effect transistor devices.
The application of these methods could help produce future technologies ranging from nanoscale electronics to energy conversion devices and optoelectronics, the researchers say.
