Electron Field Emission and Photoluminescence of Anatase Nanotube Arrays

TiO2 nanotube arrays with a high aspect ratio were grown on conductive Ti substrates by anodization in an organic electrolyte. The as-prepared TiO2 nanotubes were vertically grown and adhered well to the substrates. The photoluminescence spectrum and X-ray diffraction showed that the crystal structure of the postannealed TiO2 nanotube arrays was oxygen-defective anatase. This kind of anatase nanotube arrays exhibited efficient electron field emission even at room temperature with a low applied electric field of similar to 9 V/mu m. The emission current exceeded 70 mu A/cm(2) at an extraction voltage of 700 V.