Optical and Electric Properties of Aligned-Growing Ta<SUB>2</SUB>O<SUB>5</SUB> Nanorods

Abstract

These vertically aligned Ta2O5 nanorods were deposited on Si (100) substrates by thermal deposition in a vacuum of the order of 10−2 Torr at about 600°C. When excited by 514 nm Ar+ laser, they showed a strong photoluminescence at ∼622 nm, which was attributed to the oxygen vacancies. In addition, their dielectric constant is ∼20 in the frequency range from 1 kHz to 10 MHz, far larger than that of SiO2 and Si3N4. Due to this cone-shaped morphology, the Ta2O5 nanorods exhibited a threshold field of ∼8.5 V/μm in field emission and a field enhancement factor of 764 that are sufficiently high for field emission application.