21.15109/CONCORDA/YBGOAEHimics, LászlóLászlóHimics0000-0002-4128-130XWigner Research Centre for PhysicsGál, DávidDávidGál0000-0002-0661-8544Wigner Research Centre for PhysicsCsíkvári, PéterPéterCsíkvári0000-0001-8931-373XBudapest University of Technology and EconomicsHolomb, RomanRomanHolomb0000-0002-7383-4183Wigner Research Centre for PhysicsKoós, MargitMargitKoós8417936500Wigner Research Centre for PhysicsSulyok, AttilaAttilaSulyok55974746800Centre for Energy ResearchPécz, BélaBélaPécz0000-0002-4651-6972Centre for Energy ResearchVeres, MiklósMiklósVeres0000-0001-6687-9968Wigner Research Centre for PhysicsARP2024PhysicsFluorescent nanodiamondImpurity-related color centersIncreased photoluminescence signalSolid impurity source-assisted dopingMicrowave plasma enhanced chemical vapor depositionHimics, LászlóLászlóHimicsWigner Research Centre for Physics2023-11-092024-04-1510.1016/j.vacuum.2023.11249382920796223769424262540252199393221892777773658637814087625468400181892103890451465694414166633152392149721401326201517056text/plaintext/plaintext/plaintext/plaintext/plaintext/plaintext/plaintext/plaintext/plainimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffimage/tiffapplication/pdf1.0CC BY-NC-ND 4.0In this work, we report on a simple and easy to realize doping geometry by which the color center formation efficiency can be improved significantly in nanocrystalline diamond structures during solid impurity source-assisted microwave plasma enhanced chemical vapor deposition (MWCVD). A vertically aligned solid impurity source immersed into the CVD plasma results in diamond thin film with significantly higher color center related fluorescence signal, than the horizontal and source-free arrangements. Based on the example of negatively charged silicon-vacancy (SiV⁻) center, we demonstrated that the emission peak intensity of fluorescent nanodiamond structures prepared in such a way can be 7–10 times enhanced without significant alteration of the crystal quality. The observed phenomenon is explained by the increased number of incorporated silicon impurities into the diamond nanocrystals, initiated by the beneficial conditions for the atomization of the vertically aligned impurity source, including the enlarged contact area and the elevated surface temperature. The efficiency of the method was demonstrated for thin films and individual nanocrystal structures as well. The proposed solid-phase doping source geometry can be adapted to other impurities to extend the type or improve the in-situ formation efficiency of impurity related color centers in CVD nanodiamond crystals.National Research, Development and Innovation Office – NKFIOTKA PD-134625European Union and European Social FundVEKOP-2.3.2-16-2016-00011European Union and European Social Fund2018-1.2.1-NKP-2018-00012National Research, Development and Innovation Office – NKFI2018-1.2.1-NKP