Nitrogen ion implantation for controlled nitrogen-vacancy center creation in single-and polycrystalline diamond

Year: 2026

Authors: Rashid Z., Markesevic N., Lagomarsino S., Gelli N., Giuntini L., Massi M., Sciortino S., Flatae AM., Hernandez Gomez S., Bianchini G., Wtzrner E., Wild C., Fabbri N., Agio M.

Autors Affiliation: Natl Res Council CNR, Natl Inst Opt INO, I-50019 Sesto Fiorentino, Italy; European Lab Nonlinear Spect LENS, I-50019 Sesto Fiorentino, Italy; Univ Napoli Federico II, Dipartimento Fis Ettore Pancini, Via Cintia 21, I-80126 Naples, Italy; Ist Nazl Fis Nucl, Sez Firenze, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dept Phys & Astrophys, I-50019 Sesto Fiorentino, Italy; Univ Siegen, Lab Nano Opt, D-57072 Siegen, Germany; Diamond Mat GmbH, D-79108 Freiburg, Germany.

Abstract: Precise control over the spatial distribution and charge state of nitrogen-vacancy (NV) centers in diamond is a key requirement for further advancing this platform in quantum sensing and photonic applications. Here, we investigate nitrogen ion implantation as a scalable method to engineer NV centers in bulk single-crystalline (SC) and a 5 mu m-thick polycrystalline (PC) diamond membrane. Nitrogen-doped regions (1-80 ppm) were fabricated using a 0.7 MeV ion beam and high-temperature annealing, with NV center formation verified by confocal fluorescence imaging and spectral analysis. In SC bulk diamond, we estimate the NV concentration from spectral analysis and model the fluorescence response as a function of implantation dose, capturing both the initial increase at low concentrations and a saturation behavior at higher doses due to quenching mechanisms. In contrast, PC diamond membranes show a weaker dependence at low implantation fluences, consistent with pre-existing nitrogen impurities, thus making a statistical model significantly more complex. The activation yield is found to be of the order of 1%, which is lower than in N-rich diamond samples, as implanted N is predominantly interstitial. Photoluminescence spectroscopy indicates that NV0 is the dominant charge state in both materials, with a laser-power-dependent redistribution between neutral and negative charge states. Optically detected magnetic resonance (ODMR) measurements in SC bulk diamond resolve the hyperfine structure and allow extraction of the dephasing time (T2*), while in PC diamond membranes, where NV centers tend to form near the grain boundaries, the ODMR signals are observed but spectral resolution is currently limited by impurities, grain-dependent NV orientations, and photoluminescence background.

Journal/Review: DIAMOND AND RELATED MATERIALS

Volume: 169      Pages from: 114134-1  to: 114134-10

More Information: The authors gratefully acknowledge fruitful discussions with Florian Sledz and Michael Kunzer. A. M. F. and M. A. acknowledge access to the infrastructure of MNaF of the University of Siegen and thank Hongcai Wang and Benjamin Butz for valuable assistance with the instrumentation and acquisition of STEM images. This work received funding from the European Defence Fund (EDF) under grant agreement 101103417-project ADEQUADE. Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Commission. Neither the European Union nor the granting authority can be held responsible for them. The authors also gratefully acknowledge financial support from the European Union’s Next Generation EU Programme through the IR0000016 I-PHOQS Infrastructure,PE0000023 NQSTI, and PRIN 2022 QUASAR. The work was also supported by the European Union’s Research and Innovation Programme Horizon Europe G.A. no. 101070546-MUQUABIS, and by ASI through the Project Laboratori congiunti ASI-CNR nel settore delle Quantum Technologies-Q-ASINO (Accordo Attuativo n.2023-47-HH.0). The Istituto Nazionale di Fisica Nucleare (INFN) under the project COLOMBA (COLOr centers by a Multiple Beam Approach) within the framework of the Commissione Scientifica Nazionale 5 (CSN5), the University of Siegen, the German Research Association (DFG) (INST 221/118-1 FUGG, 410405168), and the German Academic Exchange Serivce (DAAD) (Project Id: 57703716/2024) are also acknowledged. The authors would like to thank INFN-CHNet, the network of laboratories of the INFN for cultural heritage, for support and precious contributions in terms of instrumentation and personnel.
KeyWords: Nitrogen vacancies; Nitrogen implantation; Single-crystalline diamond; Polycrystalline membranes; Dephasing time
DOI: 10.1016/j.diamond.2026.114134