ИСТИНА

A significant change in the electronic properties has been recently demonstrated for single-walled carbon nanotubes (SWCNTs), filled with CuCl by the gas phase method. The strong p-type doping induced by encapsulated CuCl crystals provides a possibility of modification of nanotubes work function and correspondingly their field emission (FE) characteristics. Here, we present a comparative study of FE characteristics of flat films composed of pristine, annealed and doped carbon nanotubes performed using a flat phosphor screen technique. A significant increase of the threshold field was observed after annealing or doping of SWCNTs films (Fig. 1). It can be caused by the selective oxidation of the small-diameter nanotubes. This explanation is confirmed by Raman spectroscopy (Fig. 2). Meanwhile, FE characteristics of annealed and doped nanotubes coincided with each other, while the Raman spectra substantially changed due to the effective doping of CuCl. These results indicate that CuCl doping does not change the work function of the emitting tip of the carbon nanotubes.