A study on the modulation of the electrical transport by mechanical straining of individual titanium dioxide nanotube

We report here, the deformation driven modulation of the electrical transport properties of an individual TiO2 nanotube via in situ transmission electron microscopy (TEM) using a scanning tunneling microscopy system. The current-voltage characteristics of each individual TiO2 nanotube revealed that under bending deformation within the elastic limit, the electrical conductivity of a TiO2 nanotube can be enhanced. High resolution TEM and electron diffraction pattern reveal that TiO2 nanotubes have tetragonal structure (a=0.378 nm, c=0.9513 nm, I41/amd). Analysis based on a metal-semiconductor-metal model suggests that in-shell, surface defect-driven conduction modes and electron–phonon coupling effect are responsible for the modulated semiconducting behaviors.