Charge transfer processes in a sodium-doped carbon composite based on fullerenes and thermally exfoliated graphite

The results of doping of a carbon composite material, in which fullerenes are located in a conductive matrix based on thermally exfoliated graphite, with a sodium dopant are presented. Charge transfer processes taking place in samples with different initial ratios of components are studied. It turns out that the electrical resistivity of the samples increases with the introduction of sodium and an increase in its content, since the mobility of the main charge carriers, which are holes as in the undoped material, decreases. The concentration of charge carriers in different types of samples varies in both directions and can increase by more than an order of magnitude. It is concluded that Na plays an ambiguous role. It can contribute not only to the generation of free electrons, but also to an additional increase in the concentration of various defects that can generate free holes and can affect, being effective traps and scattering centers, all types of charge carriers.