Preparation And Spectral Characterization Of High Concentration NV Color Centers In Diamond

The NV^-1 color centers in diamond have been considered as one of the most likely quantum computing materials in numerous quantum systems for their special energy level structures and can be controlled by optical and spin at room temperature with spin coherent of millisecond time scale.The related research based on NV^-1 color centers has made great progress which is primarily built on single NV^-1 color center or NV^-1color centers of low concentration so far,while the study on high concentration NV^-1color centers is relatively less and unsystematic.Therefore,it is important and urgent to improve the concentration of NV^-1 color centers in diamond by controlling various conditions that are of great practical significance for the research and application of high concentration NV^-1 color centers in diamond.In this paper,the preparation of high concentration NV^-1 color centers has been carefully studied via means of electron irradiation,annealing,steady state fluorescence spectroscopy and optical detection magnetic resonance system.In addition,we also studied the nonlinear optical properties of a doped metal organic frameworks.The main contents of this paper are as follows:1.We have studied the generation of NV^-1 color centers in diamond of different crystal faces under diverse electron irradiation and annealing conditions by measuring the fluorescence spectrum and the optical detection magnetic resonance spectrum,with that the concentration of color centers can be characterized and verified.The best parameters of formation were obtained accordingly.It is found that the optimum annealing condition for the NV^-1 color centers is 900?and 1 hours that are independent of electron irradiation and crystal faces.We think that when the temperature exceeds900?,the migration rate of nitrogen atoms and vacancies in diamond tend to be stable because of the influence of the diamond structure itself,thus the concentration of NV^-1color centers is no longer increasing.The annealing time of one hour is sufficient to ensure that almost all nitrogen atoms and vacancies have bound together in the diamond,the prolongation of the annealing time will not continue to increase the concentration of the NV^-1 color centers.2.We have studied the diamond with NV^-1 color centers of oriented anisotropy.The annealing treatment of diamond samples under external pressure was adopted to achieve this effect.We think that the way of external pressure can result in a distinction of the formation rate of NV^-1 color centers on different orientations.3.We have studied the nonlinear optical behavior of TCPP doped UiO-66,a zirconium based metal organic frameworks.The steady-state fluorescence spectra show that the fluorescence quenching and red shift of fluorescence peak will occur when the amount of TCPP doping reaches a certain degree.We think the former is caused by the concentration quenching effect due to the high concentration of TCPP,the latter is because of the charge transfer between the TCPP ligands and the metal centers.In addition,we found the up-conversion fluorescence phenomenon of this material,it is experimentally confirmed that the fluorescence is derived from two-photon absorption of itself.