Event Details

Growth of CVD diamond single crystals optimized for NV centre applications

The negatively charged nitrogen-vacancy centre (NV) in diamond is a point-like defect that has focused a lot of attention in the past few years due to a number of emerging quantum mechanical applications in cryptography, information processing and magnetic sensing. It has bright single photon emission and the electronic spin state of the defect can be optically read-out and manipulated leading to exceptionally long coherence time even at room temperature.

Harnessing the outstanding properties of NVs mainly relies on the progresses obtained in the synthesis of high quality and purity diamond material using the microwave plasma assisted chemical vapour deposition technique (MPACVD). Individual or ensembles of NV centres can be produced by nitrogen implantation of high-purity isotopically 12C-enriched CVD diamond plates. On the other hand, the direct creation of NVs during growth allows creating defects with improved properties in terms of coherence time and orientation as compared to implantation. The requirements though are very challenging and are setting an increasing pressure to the diamond synthesis capabilities by MPACVD. They include the control of NV creation yield and density over a wide range of concentration, from a few ppb to a few ppm and the control of defects spatial localization both in-depth (creation of delta-doped layers for example) and in-plane (creation of arrays). Moreover the ability to promote one orientation among the 4 possible axes of the NV dipole by growing on specific orientations such as (111) and (113) represents a strong advantage for the foreseen applications.

In this talk the growth of nitrogen-doped CVD diamond single crystals by MPACVD will be described. Special emphasis will be given to the control of the orientation and localization of NV centres and the optimization of their density and stability.