Triangular GaN-BN core-shell nanocables were synthesized by thermal chemical vapor deposition using GaN/B2O3/NH3 reaction. They consist of single-crystalline wurtzite GaN nanowires (avg. diameter = 60 nm), grown along the [010] direction, and 3 nm-thick crystalline h-BN outerlayers. The h-BN outerlayers lead to superhydrophobicity, and probably reduce the surface defects of GaN nanowires. Field emission from as-grown GaN-BN nanocables shows large current densities and low turn-on voltages, which are comparable to those of bare GaN nanowires. (c) 2006 Elsevier B.V. All rights reserved.