High-Yield Synthesis of Boron Nitride Nanosheets with Strong Ultraviolet Cathodoluminescence Emission

Abstract

Bulk quantities of hexagonal boron nitride ( h -BN) nanosheets have been synthesized via a simple template- and catalyst-free chemical vapor deposition process at 1100−1300 °C. Adjusting the synthesis and chemical reaction parameters, the thickness of the BN nanosheets can be tuned in a range of 25−50 nm. Fourier transform infrared spectra and electron energy loss spectra reveal the typical nature of sp 2 -hybridization for the BN nanosheets. It shows an onset oxidation temperature of 850 °C for BN nanosheets compared with only about 400 °C for that of carbon nanotubes under the same conditions. It reveals a strong and narrow cathodoluminescence emission in the ultraviolet range from the h -BN nanosheets, displaying strong ultraviolet lasing behavior. The fact that this luminescence response would be rather insensitive to size makes the BN nanosheets ideal candidates for lasing optical devices in the UV regime. The h -BN nanosheets are also better candidates for composite materials in high-temperature and hazardous environments.