Nitrogen-doped ultrananocrystalline diamond (UNCD) thin films functionalized with H2 are significantly affected by the sp2 hybridized carbon defects that are detected and analyzed using X-ray absorption near edge structure (XANES) and Raman spectroscopy using two different excitation wavelengths. The XANES and Raman results provide evidence for the presence of aromatic hydrocarbons and sp2 amorphous matrix in the grain boundaries when UNCD films are functionalized with H2. These hydrocarbons increase on hydrogenation leading to a decrease of the sp2-carbon defects (π* C=C bond) and an increase of sp3-carbon (σ* C–C bond). This sp3-carbon (σ* C–C bond) is evidently responsible for UNCD crystallites existence in the film structure and hence change the structural integrity, electronic structure, electrical and bonding properties. Nitrogen-doped ultrananocrystalline diamond (UNCD) thin films functionalized with H2 are significantly affected by the sp2 hybridized carbon defects that are detected and analyzed using X-ray absorption near edge structure (XANES) and Raman spectroscopy using two different excitation wavelengths. The XANES and Raman results provide evidence for the presence of aromatic hydrocarbons and sp2 amorphous matrix in the grain boundaries when UNCD films are functionalized with H2. These hydrocarbons increase on hydrogenation leading to a decrease of the sp2-carbon defects (π* C=C bond) and an increase of sp3-carbon (σ* C–C bond). This sp3-carbon (σ* C–C bond) is evidently responsible for UNCD crystallites existence in the film structure and hence change the structural integrity, electronic structure, electrical and bonding properties.
Relation:
Japanese Journal of Applied Physics 51(9), 095201(5pages)