Catalyst-free growth of mono- and few-atomic-layer boron nitride sheets by chemical vapordeposition

Abstract

Boron nitride (BN) is a wide bandgap semiconductor with a structure analogousto graphite. Mono- and few-atomic-layer BN sheets have been grown on siliconsubstrates by microwave plasma chemical vapor deposition from a gas mixture ofBF3–H2–N2 without using any catalysts. Growth of the BN sheets can be ascribed to theetching effects of the fluorine-containing gases and the thickness control down tomono- and few-atomic-layers was realized by decreasing the concentrations ofBF3 andH2 inN2. A largedecrease of the BF3 and H2 concentrations was achieved by increasing the gas flow rate ofN2 and keepingthe BF3 and H2 flow rates constant and the mono- and few-atomic-layered BN sheets were obtained at theBF3,H2 andN2 flow rates of 3, 10, and 1200 sccm. The present mono- and few-atomic-layer BN sheetsare promising for applications in catalyst supports, composites, gas adsorption,nanoelectronics, etc.