Triangular GaN–BN core–shell nanocables: Synthesis and field emission

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 [0 1 0] 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.