Photoexcitation electron paramagnetic resonance studies on nickel-related defects in diamond

Abstract

Measurements of the electron paramagnetic resonance (EPR) upon photoexcitation are reported on Ni defects in diamonds grown with Nicontaining solvent/catalysts. The temperature dependence of the W8 EPR spectrum photoquenching shows that the relaxation of substitutional Ni − s upon electron ionization is very small, corroborating the interpretation that the previously reported photoinduced effects with thresholds at 2.5 and 3.0 eV correspond to two complementary photoionization transitions involving Ni s . Photoinduced behaviour of the NIRIM1 EPR centre favours the interstitial Ni + i model for this defect and suggests that the Ni 0/+ i level is located at 1.98±0.03 eV below the conduction band. In N-doped diamond, Ni i is more likely to appear in the neutral state, undetectable by EPR, whereas at substitutional sites Ni − s is revealed. Observation of a strong AB2 EPR signal photoquenching and simultaneous detection of different spectral dependencies of the EPR intensity for other defects determine an electron photoionization energy of 1.67±0.03 eV for the AB2. The implications of the obtained data for the identification of the AB defects' structure are discussed. Our study shows that Ni defects exhibit a weak electron-lattice interaction. The importance of the stronger spin-orbit coupling in these centres as compared to other defects in diamond is discussed. Assuming direct intercentre charge transfer from N s , a theoretical description of the photoionization kinetics is proposed to explain the observed photoresponse of Ni defects.

Nickel doping of nitrogen enriched CVD‐diamond for the production of single photon emitters

“…However, up to now research was mainly focused on nickel (Ni)‐related defect centres in synthetic diamonds grown by the HPHT method 13–19. A practical operation of quantum devices, based on nickel–nitrogen centres, requires the reproducible generation of nickel–nitrogen centres in diamond nanocrystals, as well as in high quality single crystals.…”

Strain-based Spin Manipulation on Substitutional Nickel in Silicon Carbide

“…Through the demonstration of electron paramagnetic resonance, photoluminesence and optical absorption, numerous nickel-related defects has been identified in the diamond, including substitutional nickel 1 , nickel-vacancy 2 and nickel-vacancy-nitrogen complexes (NE centers) 3 . Several theoretical approaches have been used to investigate these nickel-related defects' structural and electronic properties [4][5][6] . Experimentally, it has been reported that NE8 center can be an excellent infrared single-photon source at room temperature [7][8][9] .…”

First principles investigations of single dopants in diamond and silicon carbide

“…There are rare reports on the synthesis of hexagonal SiC nanowires [145,146]. The preferential growth direction of 3C SiC nanowire can be manipulated to fall along the [111], [100] and [112] directions.…”

“…[111] [112] [111] [110] C H Si Since the characteristics of SiC nanowire can be controlled with such a high degree of freedom, quite a bit of choice will be available when we introduce the nickel dopant into the nanowire. We need to determine the polytypes and crystal direction of SiC nanowire before starting calculations.…”

“…Through the demonstration of electron paramagnetic resonance, photoluminesence and optical absorption, numerous nickel-related defects has been identified in the diamond, including substitutional nickel [107], nickel-vacancy [108] and nickel-vacancy-nitrogen complexes (NE centers) [109]. Several theoretical approaches have been used to investigate these nickel-related defect's structural and electronic properties [110][111][112]. Experimentally, it has been reported that the NE8 center can be an excellent infrared single-photon source at room temperature [113][114][115].…”