“…5,6 Several doping methods have been developed for nanotubes, including exposure to gaseous molecules, 7,8 annealing in vacuum 9 or in inert gas, 10,11 and adsorption of molecules. [12][13][14] On the other hand, owing to their size and geometry, SWCNTs also provide a unique opportunity for nanoscale engineering of novel one-dimensional systems, created by self-assembly of molecules inside the SWCNT's hollow core. [15][16][17][18] It has been experimentally shown that fullerenes, metallofullerenes, or organic molecules can be inserted into SWCNTs, forming a peapodlike structure.…”