A stable, low turn-on field of SnO₂ : Sb–SiO₂core–shell nanocable emitters

Abstract

Nanocables have been formed with Sb-doped SnO2 (SnO2 : Sb) cores and SiO2 shells. First, SnO2 : Sb nanowires were synthesized by a vapour–liquid–solid process at 900 °C. Subsequently, thin SiO2 shells were deposited onto the surfaces of these SnO2 : Sb nanowires. Thin-film x-ray diffraction showed that all the as-synthesized core–shell nanocables had a single-phase SnO2 rutile structure. Field emission scanning electron microscopy revealed that the nanocables had diameters of 80–140 nm and lengths of up to several hundred micrometres. As-synthesized SnO2 : Sb–SiO2 core–shell nanocables revealed an extremely low turn-on field, ~0.35 V µm−1, which was seven times lower than the ~2.3 V µm−1 field of SnO2 : Sb nanowires.