Sb-doped SnO2 wire: Highly stable field emitter

Field emission investigations of a single Sb-doped SnO2 wire synthesized by thermal evaporation have been carried out in conventional field emission geometry under ultrahigh vacuum. An onset field required to draw a current of 1 nA has been reproducibly observed to be 9.5×103 V/μm. A current density of 5.88×103 A/cm2 has been drawn with an applied field of 2×104 V/μm. The Fowler–Nordheim plot, obtained from the current–voltage (I–V) measurements, shows linear nature in accordance with the quantum mechanical tunneling phenomenon. The field enhancement factor has been estimated to be 26,500 cm−1, indicating that the emission is from the nanometric features of the Sb-doped SnO2 wire. The current–time (I–t) measurement shows high current stability without severe deviations from the initial set value of 1 μA.