Reduced work function and improved field emission stability of ZrC nanowires upon surface oxidation

The field-emission characteristics of zirconium carbide (ZrC) nanowire with an oxidized surface are studied. When the ZrC nanowire is processed to introduce an oxidized surface, its field-emission performance is improved significantly, exhibiting a high field-emission current and enhanced emission current stability with a fluctuation of 1.7% in a vacuum of 6 × 10−8 Pa. Furthermore, a reduced turn-on voltage of the ZrC nanowire after oxidation was observed in the field-emission measurement, which is attributed to a reduction of the work function of the ZrC nanowire after oxidation treatment. Density functional theory calculations have also been performed to validate the mechanisms responsible for the improvement of field-emission stability and reduction in the work function of the ZrC nanowire.