Field-emission properties of TiO2 nanowire arrays

Aligned TiO2 nanowire arrays were fabricated onto Si wafers by a simple thermal deposition (PVD) method. Scanning electron microscopy and high-resolution transmission electron microscopy observations confirm that the as-prepared TiO2 nanowires are single-crystalline and of high purity. Field emission measurements showed that the TiO2 nanowire arrays could provide stable, high-current electron emission at a low voltage. The emission current monitored over a period of 24 h fluctuated gently but did not show degradation. The cathode-luminescence (CL) images captured by a CCD camera were very bright and their CL intensity was homogeneous. This remarkable performance reveals that TiO2 nanowire arrays are well suited for commercial use in electron devices, particularly flat panel displays.