“…That is why the conclusions about the direction of charge transfer in later reports [306,307,[310][311][312][313][314][315][316][317]328] were no longer exclusively drawn from Raman spectroscopy ( Table 2). The charge transfer from the nanotube walls to the incorporated substances and shift of the SWCNT Fermi level was determined as a result of analysis of the C 1s Xray photoelectron spectra of nanotubes filled with Gd@C 82 molecules [49,256], erbium chloride [304], halogenides of silver [306], cadmium [316,317], copper [307], iron [310], nickel [312], manganese [313], zinc [314,317], cobalt bromide [311], terbium chloride [317], thulium chloride [315] and gallium selenide [315,328], and comparison of the spectra of filled nanotubes with the spectrum of pristine SWCNTs, which is a 98 narrow peak with the maximum at 284.65 eV binding energy and the FWHM of 0.4 eV [79] ( Table 2).…”