Synthesis of SiV diamond particulates via the microwave plasma chemical deposition of ultrananocrystalline diamond on soda lime glass fibers
We report the synthesis of silicon vacancy (SiV) incorporated spherical shaped ultrananocrystalline diamond (SiV UNCD) particulates (size ~1 mm) with bright luminescence at 738 nm. For this purpose, different granular structured polycrystalline diamond films and particulates were synthesized by using three different kinds of growth plasma conditions on the three types of substrate materials in the microwave plasma enhanced CVD process. The grain size dependent photoluminescence properties of nitrogen vacancy (NV) and SiV color centers have been investigated for different granular structured diamond samples. The luminescence of NV center and the associated phonon sidebands, which are usually observed in microcrystalline diamond and nanocrystalline diamond films, were effectively suppressed in UNCD films and UNCD particulates. Micron sized SiV UNCD particulates with bright SiV emission has been attained by transfer of SiV UNCD clusters on soda lime glass fibers to inverted pyramidal cavities fabricated on Si substrates by the simple crushing of UNCD/soda lime glass fibers in deionized water and ultrasonication. Such a plasma enhanced CVD process for synthesizing SiV UNCD particulates with suppressed NV emission is simple and robust to attain the bright SiV UNCD particulates to employ in practical applications.