Field emission properties of TiO2 nanotubes fabricated on Ti wire

Publication date: Available online 16 May 2019Source: Materials Chemistry and PhysicsAuthor(s): Ghafar Ali, Muhammad MaqboolAbstractThe present work reports the field emission (FE) properties of well-aligned TiO2 nanotubes (TNTs) grown on Ti wire. Vertically-oriented, and highly-ordered TNTs with high aspect ratio are synthesized on Ti wire by electrochemical anodization in ethylene glycol (EG) electrolyte containing a small amount of ammonium fluoride (NH4F) and de-ionized (DI) water. The as-anodized TNTs have been characterized using FESEM, HRTEM, EDAX, XRD, and XPS. FESEM study shows that the average diameter of the nanotubes is ∼ 90 nm and the wall thickness is ∼ 25 nm. GAXRD and HRTEM analyses indicate that the as-anodized TNTs are amorphous. EDX analysis confirms that TNTs are composed of Ti and O along with considerable amount of F. XPS results reveal the oxide state of TiO2. FE studies of the nanotubes showed that the turn-on field is 6 V/μm with corresponding emission current density of ∼10 μA/cm2 and field enhancement factor (β) of ∼ 1000. The emission current increases exponentially with increase in applied field and reaches to the maximum value of ∼150 μm at 15 V/μm. The FE properties of TNTs on Ti wire show their potential applications in the future display devices as a point electron source with small optical size. It can also be a good candidate for the fabrication of miniature X-rays tubes for industrial and medical applications.
Source: Materials Chemistry and Physics - Category: Materials Science Source Type: research