Laser-Synthesis of NV-Centers-Enriched Nanodiamonds: Effect of Different Nitrogen Sources.

Luca Basso,Massimo Cazzanelli,Antonio Miotello,Mirko Sacco,Michele Orlandi,Angelo Bifone,Alessandro Barge,Nicola Bazzanella

doi:10.3390/mi11060579

Abstract

Due to the large number of possible applications in quantum technology fields—especially regarding quantum sensing—of nitrogen-vacancy (NV) centers in nanodiamonds (NDs), research on a cheap, scalable and effective NDs synthesis technique has acquired an increasing interest. Standard production methods, such as detonation and grinding, require multistep post-synthesis processes and do not allow precise control in the size and fluorescence intensity of NDs. For this reason, a different approach consisting of pulsed laser ablation of carbon precursors has recently been proposed. In this work, we demonstrate the synthesis of NV-fluorescent NDs through pulsed laser ablation of an N-doped graphite target. The obtained NDs are fully characterized in the morphological and optical properties, in particular with optically detected magnetic resonance spectroscopy to unequivocally prove the NV origin of the NDs photoluminescence. Moreover, to compare the different fluorescent NDs laser-ablation-based synthesis techniques recently developed, we report an analysis of the effect of the medium in which laser ablation of graphite is performed. Along with it, thermodynamic aspects of the physical processes occurring during laser irradiation are analyzed. Finally, we show that the use of properly N-doped graphite as a target for laser ablation can lead to precise control in the number of NV centers in the produced NDs.

Highlights

Nitrogen-vacancy (NV) centers attracted great interest and research activity for many emerging applications in quantum technologies [1,2,3] due to the unique properties of this color center, such as its extremely long spin-coherence times [4] and easiness in spin manipulation and readout [5]
We demonstrate the synthesis of NV-fluorescent NDs through pulsed laser ablation of an N-doped graphite target
We show that the use of properly N-doped graphite as a target for laser ablation can lead to precise control in the number of NV centers in the produced NDs

Summary

Introduction

Nitrogen-vacancy (NV) centers attracted great interest and research activity for many emerging applications in quantum technologies [1,2,3] due to the unique properties of this color center, such as its extremely long spin-coherence times [4] and easiness in spin manipulation and readout [5]. For the development of these applications, the production of NDs remains a challenge, given the difficulties and drawbacks of the standard production techniques, namely detonation [23] and milling [24] These procedures do not allow good control in tailoring NDs size [25] and nitrogen doping concentration [26]. We compare the different NV centers’ production efficiency of the recently developed fluorescent NDs laser ablation synthesis techniques, namely the ablation of the N-doped graphite in water [35], gaseous [36] and liquid nitrogen (LN2) [37]. The produced sample is fully characterized in its structural and optical properties It shows a strong photoluminescence (PL) emission and a typical NV− center optically detected magnetic resonance (ODMR) fingerprint, proving the NV-hosting NDs formation upon laser ablation. We showed that this particular N-doped target could open a way to obtain NDs with a tunable concentration of NV centers

N-Doped Graphite Target Preparation

Pulsed Laser Ablation

Characterization Techniques

NDs Synthesis and Characterization

NDs Production Yield