Yang Meng

Change in Spatial Distribution of State Densities of Carbon Nanotubes Under Anisotropic Strain Field

In any electronic devices and sensors, unexpected changes in their function occur due to internal strain caused by contact of different materials which leads to thermal deformation or lattice mismatch. Thus, understanding of the effect of strain on electronic properties of carbon nanotubes (CNTs) is indispensable for assuring the reliability of CNTs-based electronic devices and for developing new electronic devices and sensors. In this study, the change in spatial distribution of state densities of zigzag CNTs under radial strain is analyzed by using first-principles calculation. The analysis shows that when a radial strain is applied to a CNT, its state densities are localized at high curvature regions. Such localization of state densities decrease their energies, and then decrease the band gap. In addition, since the behavior of the state energy under the radial strain is dominated by its spatial distribution, the strain sensitivity of CNTs depends on their chirality. The founding gives a guideline on how to fabricate high-performance novel CNTs devices, sensors, for example, biaxial strain sensor.© 2014 ASME