Highly crystalline 5H-polytype of sp3-bonded boron nitride prepared by plasma-packets-assisted pulsed-laser deposition:: An ultraviolet light emitter at 225 nm

Highly crystalline 5H-polytypic form of sp(3)-bonded boron nitride (BN) was grown by pulsed-laser-vaporization of BN, where synchronous reactive-plasma packets assisted the crystal growth in the vapor phase. The structure of the product crystallites (similar to5 mum) was confirmed by using transmission electron diffraction and electron energy loss spectroscopy. This material proved to have a sharp and dominant band at 225 nm by cathodoluminescence at room temperatures and corresponding monochromatic images revealed that they uniformly emitted the ultraviolet light. Considering that cubic BN has already been doped as p- and n-type semiconductors, this material may be applied to the light-emitting devices working at almost the deepest limit of the UV region that is functional without vacuum. (C) 2002 American Institute of Physics.