Resonant Raman scattering of diamondlike amorphous carbon films

Raman spectra of diamondlike amorphous carbon (a-C) films prepared by the sputtering method have been measured as a function of the excitation wavelength. The Raman spectral profiles vary sensitively, reflecting the change of absorption spectra associated with π-π* electronic transitions with the hydrogen content of the films. From a comparison between Raman and electronic absorption spectra, it is confirmed that the Raman spectral variation with the excitation wavelength is due to the π-π* resonant Raman scattering from π-bonded (sp2) carbon clusters.