Spectroscopy of thin nanodiamond layers and membranes

Abstract Optical and photoelectrical spectroscopy was applied to the study of submicron thin nanocrystalline diamond films and membranes on silicon and glass substrates, together with Raman and luminescence spectroscopy. Fourier transform photocurrent spectroscopy was used to study electronic defect states in the nanodiamond films. The deposited films are smooth and fully transparent, with Raman spectra approaching that of polycrystalline diamond and a hydrogen concentration below 0.1%. We observed several peaks in the infrared photocurrent spectrum of nanocrystalline diamond, connected with surface states and defects, in the range 0.25–0.6 eV above the valence band edge.