2D inverse periodic opal structures in single crystal diamond with incorporated silicon-vacancy color centers

Well-ordered opal-diamond composite and inverted opal structure in single crystal (SC) diamond have been prepared by microwave plasma CVD. The process is based on epitaxial diamond growth through a monolayer of densely packed SiO₂ spheres placed on a (100) HPHT diamond substrate. Finally, the opal monolayer with ≈ 600 nm sphere diameter was completely embedded in SC CVD diamond forming a new type of ordered diamond composite. In addition, the inverse opal structures (air cavities in diamond) were produced by SiO₂ etching. The XRD analysis confirmed the single crystal nature of the deposit. The photoluminescence spectrum exhibits a strong peak at 738 nm wavelength of silicon-vacancy defects in diamond, indicating Si doping during the CVD process. The optical properties of the diamond structures were evaluated also with Raman spectroscopy and optical reflection spectrometry. The developed epitaxy-through-mask approach is considered as a potential strategy to fabricate multilayered (3D) SC diamond photonic crystals.