Single-walled carbon nanotubes as a dopant in p-type cuprous oxide films

p-type cuprous oxide (Cu₂O) films doped with single-walled carbon nanotubes (SWCNTs) were synthesized using the two-step process of electrochemical co-deposition and subsequent thermal oxidation. SWCNTs are known to act as a conducting pathway in various SWCNT-based composite materials because of their low electrical resistivity in the longitudinal direction. However, they act as an electron acceptor dopant rather than a carrier pathway in p-type Cu₂O. Results show that the doping of SWCNTs in Cu ₂O films increases the hole concentration and decreases the carrier mobility with increasing dopant concentration. As a result, the electrical resistivity decreased from 290 to 0.8 Ω cm as the amount of dopant increased. The electronic energy band structure, as determined by X-ray and ultraviolet photoelectron spectroscopy, revealed that the doping of SWCNTs moved the Fermi levels of Cu₂O films toward the valence band maximum by 0.24 eV. This confirms that the SWCNTs act as an electron acceptor and increase the hole concentration and electrical conductivity of the Cu₂O films, despite the lower mobility. Crown