Picosecond photoluminescence decay of Si-doped chemical-vapor-deposited diamond films

Photoluminescence decay times and quantum yields were measured at 77 K in the spectra of two Si-doped diamond films grown by the chemical-vapor deposition technique. A decay time of 950 ps For both films and a quantum yield of 0.05 for one film were determined for the Si center zero-phonon optical transition at 737 nm (1.6823 eV). Two broad subbands with decay times of 55 and 650 ps and yields of 8x10(-4) were observed in the luminescence at 600, 650, and 720 nm and ascribed to an sp(2) nondiamond carbon phase.