High mobility n-type conductive ultrananocrystalline diamond and graphene nanoribbon hybridized carbon films

We have prepared high mobility n-type conductive hybridized carbon films with microstructures dominantly comprising of ultrananocrystalline diamond (UNCD) and graphene nanoribbons (GNR) via oxygen ion (O+) implantation and thermal oxidization annealing. The results indicate that GNRs appear in the grain boundaries of 1011-1013 cm−2 O+-implanted hybridized carbon films after 800-900 °C annealing. The O+-implanted diamond grains terminated by CO bonds give conductivity and GNRs construct a conductive network surrounding diamond grains, thus n-type Hall mobility attains to high values of 126-303 cm2 V−1 s−1. The results of Raman spectra, high resolution transmission electron microscopy and near edge X-ray absorption fine structure show that the contents of trans-polyacetylene chains decrease while GNRs appear in grain boundaries. It means that some trans-polyacetylene chains transit to GNRs. The calculation by using first-principles based nudged elastic band method determines a low activation barrier value of 0.87 eV for the transition from trans-polyacetylene chains to GNRs, confirming that GNRs are originated from the fact that two trans-polyacetylene chains approach to connect each other accompanied by the hydrogen desorption in the chains. Our results supply a novel hybridized carbon films which can be applied in the areas of electronic devices, field emission displayer and electrochemical electrodes.