Field Emission Characteristics of Double Walled TiO2 Nanotubes

Abstract

Double walled TiO2 nanotubes have been synthesized by two probe anodization method on highly pure Titanium (Ti) substrate. FESEM and XRD analyses revealed the morphological and structural properties of the as-synthesized double walled TiO2 nanotubes. Investigation of their field emission characteristics in a planar diode configuration at a base pressure of 1 x 10-8 mbar has been done. The turn-on field defined for the emission current density of 10 μA/cm2 is found to be 2.1 V/μm. As the field is increased further to 2.95 V/μm maximum, a current density of 890 μA/cm2 is achieved. Current-time (I-t) measurement at a preset value of 1 μA emission current for the duration of 3 h demonstrates a robust emission current stability. The observed low turn-on field and stable electron emission makes the double walled TiO2 nanotubes a suitable emitter for various electronics devices applications.