Ionoluminescence characterization of microwave and hot-filament CVD diamonds

The ionoluminescence (IL) spectrum resulting through the interaction of proton beams with bulk samples has become an adequate technique for material characterization. In the present work, we have investigated the IL response of microwave (MW) and hot-filament (HF) CVD diamonds, by examining the radiative recombination induced by a 1.9 MeV proton beam (0.25-3.0 μA) on the diamond films. The IL spectral characteristics were different for dissimilar diamond films. The HFCVD diamond showed two broad IL bands around 300-450 nm and/or 500-750 nm. The bands may be associated to intrinsic defects and to [N-V] and [N-V-N] centers. In some cases the H3-center band around 503 nm (2.46 eV) was also clearly depicted. The HFCVD diamond displayed mainly a well-defined dislocation-related A band centered at 440 nm (2.82 eV). The results indicated that the IL technique is a practical tool to obtain spectral information about defects and centers in CVD diamonds. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.