Abstract: A multilayer device includes a substrate having a trench extending along a first surface of the substrate. A first layer disposed on the first surface of the substrate, the first layer comprising a given surface and another surface. A dielectric layer is formed between the given surface of the first layer and the first surface of the substrate. An active region disposed on the other surface of the first layer overlying the trench, wherein at least a portion of the active region resides substantially above a region defined by the trench.

Abstract: Provided is a method for treating single-walled carbon nanotube, comprising: (1) allowing single-walled carbon nanotubes to contact with a surfactant and a dispersant sequentially in the present of a solvent, to obtain highly dispersed single-walled carbon nanotubes in which the content of single dispersed single-walled carbon nanotubes is not lower than 50 wt %, wherein, the single-walled carbon nanotubes can be dispersed in the solvent, and the surfactant and dispersant can be dissolved in the solvent; (2) employing density gradient centrifugation to sort the highly dispersed single-walled carbon nanotubes obtained in step (1). This method can effectively separate single-walled carbon nanotubes with different structural properties.