Synthesis and characterization of copper-nanocarbon films with enhanced stability

Copper-nanocarbon, called covetic, films made using pulsed laser deposition (PLD) from a target containing nominally 4 wt% carbon in the copper matrix show uniform integration of up to 4.1±0.2 wt.% C. We observe evidence of sp2 carbon in PLD Cu covetic films in XPS and a peak in the C K-edge in electron energy loss spectroscopy indicative of transitions from the 1s to π* anti-bonding unoccupied state, suggesting that the C incorporated in the film is graphitic in nature. We measure sheet resistance of 1.7 Ohm/sq and transmittance of 25% at 550 nm in a ≈27 nm thick PLD Cu covetic film after deposition. These films also show much reduced oxidation by scanning probe techniques and very stable resistance for over 120 days - significantly longer than e-beam films of the same thickness. Cu covetic films made by PLD show good promise as transparent electrodes.

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