Metals are filled inside single-walled carbon nanotubes (SWCNTs) using solution methods. They include multi-stage cleaning steps, sorting from excess salts. I filled SWCNTs with silver, copper and I investigated the clean samples after decomposition of salts to metals with Raman spectroscopy, optical absorption spectroscopy (OAS), and photoemission spectroscopy. The investigations showed that the silver and copper fillings are succsessful, this is proven by transmission electron microscopy, and other methods. The n-doping with strong modifications of spectra is observed. Metal filling is very promising for thermoelectric power generation, and copper filling was firstly made in Russia, and it was published by me in Russian journal [1,2]. This is important for approbation, and prove of results. Applications of metal filled carbon nanotubes are only possible with clean samples, and the synthesis processes of metal filled SWCNTs should be refined to obtain maximal filling ratios. The filling ratios with metal are high, and everybody can detect filling with modern techniques, Raman spectroscopy, near edge X-ray photoelectron spectroscopy, OAS, PE for applications.

[1] Kharlamova M.V., Niu J.J. Donor doping of single-walled carbon nanotubes by filling of channels with silver. Journal of Experimental and Theoretical Physics. 2012. V.115. N.3. P.485-491.

[2] Kharlamova M.V., Niu J.J. New method of the directional modification of the electronic structure of single-walled carbon nanotubes by filling channels with metallic copper from a liquid phase. JETP Letters. 2012. V.95. N.6. P.314-319.