Boron nitride nanosheets (BNNSs) protruding from boron nitride (BN) films were synthesized on silicon substrates by chemical vapor deposition technique from a gas mixture of BCl3-NH3-H-2-N-2. Parts of the as-grown nanosheets were vertically aligned on the BN films. The morphology and structure of the synthesized BNNSs were characterized by scanning electron microscopy, transmission electron microscopy, and Fourier transformation infrared spectroscopy. The chemical composition was studied by energy dispersive spectroscopy and X-ray photoelectron spectroscopy. Cathodoluminescence spectra revealed that the product emitted strong UV light with a broad band ranging from 250 to 400 nm. Field-emission characteristic of the product shows a low turn-on field of 6.5 V mu m(-1). (C) 2012 Elsevier Ltd. All rights reserved.