Phase transition in a single VO2 nano-crystal: potential femtosecond tunable opto-electronic nano-gating

The first-order semiconductor–metal Mott transition in single nano-crystal of VO2 has been observed using scanning tunneling spectroscopy. The variation of the band gap E g with an external thermal stimulus on a single VO2 nano-crystal in the temperature range of 293.5–361.0 K is reported for the first time. The corresponding tuneable I–V characteristics versus temperature could be applied in thermally or optically tunable electronic nano-gating in the femtosecond regime in view of the ultrafast dynamic in VO2.