Structural and Optical Analysis of NV Centers in Diamonds Synthesized by MPCVD With Controlled Nitrogen Doping Time

The magnetic field-dependent fluorescence properties of NV<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-}$</tex-math> </inline-formula> center defects embedded within a diamond matrix have made them a candidate for solid-state qubits for quantum computing and magnetic field sensing. Microwave plasma-assisted chemical vapor deposition (MPCVD) of diamonds with in situ nitrogen doping has provided reproducibility and uniformity in the production of NV<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-}$</tex-math> </inline-formula> centers on multiple substrates. What remains to be understood is the impact of the nitrogen doping time on the MPCVD process and its impact on the creation of NV<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-}$</tex-math> </inline-formula> centers. Analysis of the NV<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-}$</tex-math> </inline-formula>-containing diamond films has been carried out using X-ray diffraction (XRD), Raman spectroscopy, and optical microscopy. This study aims to investigate the effect of nitrogen doping time and its effect on the produced spectral lines associated with the 1333-cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> diamond Raman spectra peak, 637-nm photoluminescence NV<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}^{-}$</tex-math> </inline-formula> spectral peak, and the (111) and (220) diamond XRD peaks. Here, we demonstrate that using a Voigt model to curve fit the 637-nm P-luminescence line produces a method by which the zero phonon line can be measured. Furthermore, the Williamson–Hall plot method provided a relationship between the strain and crystal size of associated films.