ORCID Profile
0000-0002-7850-3164
Current Organisations
National Institutes for Quantum Science and Technology
,
Tohoku University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Nanomaterials | Photonics and Electro-Optical Engineering (excl. Communications) | Optical Properties of Materials | Condensed Matter Physics | Nanotechnology | Materials Engineering | Biologically Active Molecules | Composite and Hybrid Materials | Photonics, Optoelectronics and Optical Communications | Nanophotonics | Electronic and Magnetic Properties of Condensed Matter; Superconductivity | Nanobiotechnology | Optical Physics not elsewhere classified
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in the Chemical Sciences | Scientific Instruments | Expanding Knowledge in Technology | Emerging Defence Technologies | Expanding Knowledge in the Biological Sciences |
Related Links
Publications
Analysis for Radiation-Resistance of InGaP and GaAs Sub-Cells for InGaP/GaAs/Ge 3-Junction Solar Cells
Publisher: IEEE
Date: 2006
Imaging Current Paths in Silicon Photovoltaic Devices with a Quantum Diamond Microscope
Publisher: American Physical Society (APS)
Date: 18-07-2022
Fabrication of single photon centres in silicon carbide
Publisher: IEEE
Date: 12-2012
Observation of transient current induced in silicon carbide diodes by ion irradiation
Publisher: Elsevier BV
Date: 05-2003
Enhanced magnetometry with an electrically detected spin defect ensemble in silicon carbide
Publisher: AIP Publishing
Date: 05-06-2023
DOI: 10.1063/5.0154382
Abstract: Spin defects in solid-state sensors are a highly promising platform for quantum sensing, a field with far-reaching applications in a variety of industries. Here, we investigate the magnetic sensitivity of a spin defect ensemble detected electrically in a silicon carbide pn-junction diode utilizing the hyperfine-induced spin-mixing effect observed in the vicinity of zero magnetic field. To enhance the baseline sensitivity, we employ above bandgap optical excitation to generate additional electron-hole pairs as well as a balanced detection scheme to reject common-mode noise, with an ultimate sensitivity of 30 nT/Hz achieved. Both techniques are demonstrated to greatly enhance the magnetic sensitivity of the device by a total factor of ∼24, paving the way toward sub-nanotesla magnetic field sensitivities with electrical detection.
Low-loss tellurite fibers with embedded nanodiamonds
Publisher: OSA
Date: 2015
Creation and functionalization of defects in SiC by proton beam writing
Publisher: Trans Tech Publications, Ltd.
Date: 05-2017
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.897.233
Abstract: Proton beam writing was carried out into high purity semi-insulating 4H-SiC bulk substrates. Luminescent defects created in the SiC by proton beam writing using 1.7 MeV-proton micro beams were investigated at room temperature using confocal laser scanning microscope. As a result, photoluminescence peak around 900 nm associated with silicon vacancy was observed for the irradiated SiC without post implantation process such as annealing. The overall depth profile of photon counts detected from irradiated areas is in good agreement with simulated vacancy depth profile. This suggests that silicon vacancy can be applied to ion tracking detector. In addition, since silicon vacancy is known as single photon source of which spins can be controlled at RT, PBW is expected to be a useful tool to fabricate spin qubits.
The role of ion track structure on high-injection carrier dynamics in high-speed Si and III-V optoelectronic sensors
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2007
NV−–N+ pair centre in 1b diamond
Publisher: IOP Publishing
Date: 26-11-2018
Magnetically sensitive nanodiamond-doped tellurite glass fibers
Publisher: Springer Science and Business Media LLC
Date: 19-01-2018
DOI: 10.1038/S41598-018-19400-3
Abstract: Traditional optical fibers are insensitive to magnetic fields, however many applications would benefit from fiber-based magnetometry devices. In this work, we demonstrate a magnetically sensitive optical fiber by doping nanodiamonds containing nitrogen vacancy centers into tellurite glass fibers. The fabrication process provides a robust and isolated sensing platform as the magnetic sensors are fixed in the tellurite glass matrix. Using optically detected magnetic resonance from the doped nanodiamonds, we demonstrate detection of local magnetic fields via side excitation and longitudinal collection. This is a first step towards intrinsically magneto-sensitive fiber devices with future applications in medical magneto-endoscopy and remote mineral exploration sensing.
Lithographically engineered shallow nitrogen-vacancy centers in diamond for external nuclear spin sensing
Publisher: IOP Publishing
Date: 22-08-2018
Laplace DLTS study of deep defects created in neutron-irradiated n-type 4H-SiC
Publisher: Elsevier BV
Date: 12-2018
In vivo imaging and tracking of individual nanodiamonds in drosophila melanogaster embryos
Publisher: The Optical Society
Date: 20-03-2014
DOI: 10.1364/BOE.5.001250
Charge pumping electrically detected magnetic resonance of silicon carbide power transistors
Publisher: AIP Publishing
Date: 03-08-2023
DOI: 10.1063/5.0167650
Abstract: Silicon carbide (SiC) power devices are becoming central components in high voltage electronics. However, defects at interfaces and in the bulk continue to severely impact their reliability and performance. Here, we develop a charge pumping method to characterize SiC/SiO2 interface defects in fully fabricated commercial SiC power metal–oxide–semiconductor field-effect transistors (MOSFETs). The method is then used to address spin states at the SiC/SiO2 interface via charge pumping electrically detected magnetic resonance (CP-EDMR). We apply these methods to investigate the power MOSFET after electron irradiation over a dose range of 1013−1017 cm−2. We finally discuss CP-EDMR as a technique to interrogate spins during device operation for real-time monitoring of the device quality, performance, and degradation and as a probe for local magnetic fields.
Acoustomicrofluidic Concentration and Signal Enhancement of Fluorescent Nanodiamond Sensors
Publisher: American Chemical Society (ACS)
Date: 23-11-2021
DOI: 10.1021/ACS.ANALCHEM.1C03893
Abstract: Diamond nitrogen-vacancy (NV) centers constitute a promising class of quantum nanosensors owing to the unique magneto-optic properties associated with their spin states. The large surface area and photostability of diamond nanoparticles, together with their relatively low synthesis costs, make them a suitable platform for the detection of biologically relevant quantities such as paramagnetic ions and molecules in solution. Nevertheless, their sensing performance in solution is often h ered by poor signal-to-noise ratios and long acquisition times due to distribution inhomogeneities throughout the analyte s le. By concentrating the diamond nanoparticles through an intense microcentrifugation effect in an acoustomicrofluidic device, we show that the resultant dense NV ensembles within the diamond nanoparticles give rise to an order-of-magnitude improvement in the measured acquisition time. The ability to concentrate nanoparticles under surface acoustic wave (SAW) microcentrifugation in a sessile droplet is, in itself, surprising given the well-documented challenge of achieving such an effect for particles below 1 μm in dimension. In addition to a demonstration of their sensing performance, we thus reveal in this work that the reason why the diamond nanoparticles readily concentrate under the SAW-driven recirculatory flow can be attributed to their considerably higher density and hence larger acoustic contrast compared to those for typical particles and cells for which the SAW microcentrifugation flow has been shown to date.
Infrared erbium photoluminescence enhancement in silicon carbide nano-pillars
Publisher: AIP Publishing
Date: 08-10-2021
DOI: 10.1063/5.0055100
Abstract: Color centers that emit light at telecommunication wavelengths are promising candidates for future quantum technologies. A pressing challenge for the broad use of these color centers is the typically low collection efficiency from bulk s les. Here, we demonstrate enhancements of the emission collection efficiency for Er3+ incorporated into 4H-SiC surface nano-pillars fabricated using a scalable top-down approach. Optimal Er ion implantation and annealing strategies are investigated in detail. The substitutional fraction of Er atoms in the SiC lattice is closely correlated with the peak photoluminescence intensity. This intensity is further enhanced via spatial wave-guiding once the surface is patterned with nano-pillars. These results have broad applicability for use with other color centers in SiC and also demonstrate a step toward a scalable protocol for fabricating photonic quantum devices with enhanced emission characteristics.
Carrier removal in lattice-mismatched InGaP solar cells under 1-MeV-electron irradiation
Publisher: AIP Publishing
Date: 27-09-2004
DOI: 10.1063/1.1794371
Abstract: Radiation-induced majority carrier removal is investigated from n+∕p− lattice-mismatched In0.56Ga0.44P solar cells under 1-MeV-electron irradiation. The change in carrier concentration in the 1×1017cm−3p− base layer is determined using standard capacitance–voltage techniques and found to proceed at a rate Rc=1.3cm−1, in agreement with that observed in lattice-matched InGaP. However, the observation of an increased short-circuit current and short-wavelength quantum efficiency over the unirradiated values at electron fluence levels in excess of 3×1015cm−2, allows the carrier concentration from the n+ emitter layer to be measured. By modeling the quantum efficiency of these solar cells, it is shown that the main photoresponse from these lattice-mismatched solar cells is due to drift transport, making the spectral response highly sensitive to changes in the width of the depletion region. Using this technique, the carrier concentration in the 2×1018cm−3 n+ emitter layer is found to be reduced to 1×1018cm−3 after exposure to an electron fluence of 3×1015cm−2.
Fluorescent Nanodiamonds Embedded in Poly-ε-Caprolactone Fibers as Biomedical Scaffolds
Publisher: American Chemical Society (ACS)
Date: 05-11-2020
Effects of a low-energy proton irradiation on n+/p-AlInGaP solar cells
Publisher: Elsevier BV
Date: 04-2006
Proximal nitrogen reduces the fluorescence quantum yield of nitrogen-vacancy centres in diamond
Publisher: IOP Publishing
Date: 03-2022
Abstract: The nitrogen-vacancy colour centre in diamond is emerging as one of the most important solid-state quantum systems. It has applications to fields including high-precision sensing, quantum computing, single photon communication, metrology, nanoscale magnetic imaging and biosensing. For all of these applications, a high quantum yield of emitted photons is desirable. However, diamond s les engineered to have high densities of nitrogen-vacancy centres show levels of brightness varying significantly within single batches, or even within the same s le. Here we show that nearby nitrogen impurities quench emission of nitrogen-vacancy centres via non-radiative transitions, resulting in a reduced fluorescence quantum yield. We monitored the emission properties of nitrogen-vacancy centre ensembles from synthetic diamond s les with different concentrations of nitrogen impurities. All s les were irradiated with high energy electrons to create high densities of nitrogen-vacancy centres relative to the concentration of nitrogen impurities. While at low nitrogen densities of 1.81 ppm we measured a lifetime of 13.9 ns, we observed a strong reduction in lifetime with increasing nitrogen density. We measure a lifetime as low as 4.4 ns at a nitrogen density of 380 ppm. The change in lifetime matches a reduction in relative fluorescence quantum yield from 77.4% to 32% with an increase in nitrogen density from 88 ppm to 380 ppm, respectively. These results will inform the conditions required to optimise the properties of diamond crystals devices based on the fluorescence of nitrogen-vacancy centres. Furthermore, this work provides insights into the origin of inhomogeneities observed in high-density nitrogen-vacancy ensembles within diamonds and nanodiamonds.
M center in 4 H -SiC is a carbon self-interstitial
Publisher: American Physical Society (APS)
Date: 28-05-2021
Amplification by stimulated emission of nitrogen-vacancy centres in a diamond-loaded fibre cavity
Publisher: Walter de Gruyter GmbH
Date: 28-09-2020
Abstract: Laser threshold magnetometry using the negatively charged nitrogen-vacancy (NV − ) centre in diamond as a gain medium has been proposed as a technique to dramatically enhance the sensitivity of room-temperature magnetometry. We experimentally explore a diamond-loaded open tunable fibre-cavity system as a potential contender for the realisation of lasing with NV − centres. We observe lification of the transmission of a cavity-resonant seed laser at 721 nm when the cavity is pumped at 532 nm and attribute this to stimulated emission. Changes in the intensity of spontaneously emitted photons accompany the lification, and a qualitative model including stimulated emission and ionisation dynamics of the NV − centre captures the dynamics in the experiment very well. These results highlight important considerations in the realisation of an NV − laser in diamond.
Double negatively charged carbon vacancy at the h- and k-sites in 4H-SiC: Combined Laplace-DLTS and DFT study
Publisher: AIP Publishing
Date: 16-02-2018
DOI: 10.1063/1.5011124
Abstract: We present results from combined Laplace-Deep Level Transient Spectroscopy (Laplace-DLTS) and density functional theory studies of the carbon vacancy (VC) in n-type 4H-SiC. Using Laplace-DLTS, we were able to distinguish two previously unresolved sub-lattice-inequivalent emissions, causing the broad Z1/2 peak at 290 K that is commonly observed by conventional DLTS in n-type 4H-SiC. This peak has two components with activation energies for electron emission of 0.58 eV and 0.65 eV. We compared these results with the acceptor levels of VC obtained by means of hybrid density functional supercell calculations. The calculations support the assignment of the Z1/2 signal to a superposition of emission peaks from double negatively charged VC defects. Taking into account the measured and calculated energy levels, the calculated relative stability of VC in hexagonal (h) and cubic (k) lattice sites, as well as the observed relative litude of the Laplace-DLTS peaks, we assign Z1 and Z2 to VC(h) and VC(k), respectively. We also present the preliminary results of DLTS and Laplace-DLTS measurements on deep level defects (ET1 and ET2) introduced by fast neutron irradiation and He ion implantation in 4H-SiC. The origin of ET1 and ET2 is still unclear.
Visitors' wayfinding strategies and navigational aids in unfamiliar urban environment
Publisher: Informa UK Limited
Date: 12-2019
Fluorescent Silicon Carbide Nanoparticles
Publisher: Wiley
Date: 17-07-2021
Abstract: Silicon carbide (SiC) is an indirect wide band gap semiconductor that is utilized in many industrial applications due to its extreme physical properties. SiC nanoparticles (NPs) exhibit a versatile surface chemistry, fluoresce from the ultraviolet to the near‐infrared spectral ranges, and their sizes can be tuned from one to hundreds of nanometers. Yet, fluorescent SiC NPs have received far less attention by the scientific community. This review summarizes the state‐of‐the‐art in fluorescent SiC NPs. Nanoparticle fabrication methods, characterization techniques, nanoparticle surface chemistry, and SiC NPs fluorescence properties are assessed in detail. Atomic defects and impurities in the SiC crystal lattice (so‐called color centers), surface‐induced fluorescence, quantum confinement, and band‐edge fluorescence are identified as the main sources of fluorescence in SiC NPs. While many color centers are reported in bulk SiC, only few are identified in SiC NPs and interface‐related defects remain poorly understood, creating enormous potential for scientific discovery. Finally, an overview of demonstrated and emerging potential applications of SiC NPs in the areas of bioimaging and quantum sensing is provided.
Optical properties of neodymium ions in nanoscale regions of gallium nitride: erratum
Publisher: The Optical Society
Date: 25-01-2021
DOI: 10.1364/OME.420328
Color centers enabled by direct femto-second laser writing in wide bandgap semiconductors
Publisher: MDPI AG
Date: 31-12-2021
DOI: 10.3390/NANO11010072
Abstract: Color centers in silicon carbide are relevant for applications in quantum technologies as they can produce single photon sources or can be used as spin qubits and in quantum sensing applications. Here, we have applied femtosecond laser writing in silicon carbide and gallium nitride to generate vacancy-related color centers, giving rise to photoluminescence from the visible to the infrared. Using a 515 nm wavelength 230 fs pulsed laser, we produce large arrays of silicon vacancy defects in silicon carbide with a high localization within the confocal diffraction limit of 500 nm and with minimal material damage. The number of color centers formed exhibited power-law scaling with the laser fabrication energy indicating that the color centers are created by photoinduced ionization. This work highlights the simplicity and flexibility of laser fabrication of color center arrays in relevant materials for quantum applications.
Magnetic field-induced enhancement of the nitrogen-vacancy fluorescence quantum yield
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR02093G
Abstract: The nitrogen-vacancy (NV) centre in diamond is a remarkable optical defect with broad applications. We demonstrate that its fluorescence emission is enhanced at high magnetic fields with low excitation power.
Detection of Paramagnetic Spins with an Ultrathin van der Waals Quantum Sensor
Publisher: American Chemical Society (ACS)
Date: 05-07-2023
Nanodiamond in tellurite glass Part II: Practical nanodiamond-doped fibers
Publisher: The Optical Society
Date: 09-12-2015
DOI: 10.1364/OME.5.000073
Optical properties of neodymium ions in nanoscale regions of gallium nitride: erratum
Publisher: The Optical Society
Date: 25-01-2021
Homoepitaxial diamond film growth: High purity, high crystalline quality, isotopic enrichment, and single color center formation (Phys. Status Solidi A 11∕2015)
Publisher: Wiley
Date: 11-2015
Quenching of impact ionization in heavy ion induced tracks in wide bandwidth Si avalanche photodiodes
Publisher: IEEE
Date: 09-2007
Nitrogen-Terminated Diamond Surface for Nanoscale NMR by Shallow Nitrogen-Vacancy Centers
Publisher: American Chemical Society (ACS)
Date: 24-01-2019
A silicon carbide room-temperature single-photon source
Publisher: Springer Science and Business Media LLC
Date: 17-11-2014
DOI: 10.1038/NMAT3806
Abstract: Over the past few years, single-photon generation has been realized in numerous systems: single molecules, quantum dots, diamond colour centres and others. The generation and detection of single photons play a central role in the experimental foundation of quantum mechanics and measurement theory. An efficient and high-quality single-photon source is needed to implement quantum key distribution, quantum repeaters and photonic quantum information processing. Here we report the identification and formation of ultrabright, room-temperature, photostable single-photon sources in a device-friendly material, silicon carbide (SiC). The source is composed of an intrinsic defect, known as the carbon antisite-vacancy pair, created by carefully optimized electron irradiation and annealing of ultrapure SiC. An extreme brightness (2×10(6) counts s(-1)) resulting from polarization rules and a high quantum efficiency is obtained in the bulk without resorting to the use of a cavity or plasmonic structure. This may benefit future integrated quantum photonic devices.
Engineering Single Defects in Silicon Carbide Bulk, Nanostructures and Devices
Publisher: Trans Tech Publications, Ltd.
Date: 05-2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.858.312
Abstract: We will review recent demonstrations of single photon emission in different silicon carbide (SiC) polytypes, in both bulk and nano-structured form. Due to well established doping, and micro- and nanofabrication procedures deep defects photoluminescence (PL) can be electrically excited and incorporated in SiC nanomaterials. Finally we will report on preliminary results to incorporate near infrared defects in SiC nanoparticles.
Defect levels in low-doped 4H-SiC Schottky barrier diodes detected by using alpha particles
Publisher: IEEE
Date: 12-2012
Dopant effects on solid phase epitaxy in silicon and germanium
Publisher: AIP Publishing
Date: 02-2012
DOI: 10.1063/1.3682532
Abstract: The kinetics of dopant-enhanced solid phase epitaxy (SPE) are studied in amorphous silicon (a-Si) and germanium (a-Ge) layers formed by ion implantation. Implanted Sb dopants into a-Ge up to a concentration of 1 × 1020 cm−3 are considered and compared to As implanted layers at similar concentrations. Although an active Sb concentration above the solubility limit is achieved, a significant portion of the implanted atoms are not. P, As, and B enhanced SPE rates in Si from the literature are also considered. The relative velocities of P and As in Si is similar to that of As and Sb in Ge. Theoretical predictions using a simple form of the generalized Fermi level shifting model, which incorporates both dopant and dopant-induced stress effects, is shown to agree well with the data. A single set of two parameters are determined, which describe the dopant enhanced SPE data well independent of dopant species and concentration.
Deep-level defects introduced by 1 MeV electron radiation in AlInGaP for multijunction space solar cells
Publisher: AIP Publishing
Date: 11-2005
DOI: 10.1063/1.2115095
Abstract: Presented in this paper are 1 MeV electron irradiation effects on wide-band-gap (1.97 eV) (Al0.08Ga0.92)0.52In0.48P diodes and solar cells. The carrier removal rate estimated in p-AlInGaP with electron fluence is about 1cm−1, which is lower than that in InP and GaAs. From high-temperature deep-level transient spectroscopy measurements, a deep-level defect center such as majority-carrier (hole) trap H2 (Eν+0.90±0.05eV) was observed. The changes in carrier concentrations (Δp) and trap densities as a function of electron fluence were compared, and as a result the total introduction rate, 0.39cm−1, of majority-carrier trap centers (H1 and H2) is different from the carrier removal rate, 1cm−1, in p-AlInGaP. From the minority-carrier injection annealing (100mA∕cm2), the annealing activation energy of H2 defect is ΔE=0.60eV, which is likely to be associated with a vacancy-phosphorus Frenkel pair (Vp-Pi). The recovery of defect concentration and carrier concentration in the irradiated p-AlInGaP by injection relates that a deep-level defect H2 acts as a recombination center as well as compensator center.
Homoepitaxial diamond film growth: High purity, high crystalline quality, isotopic enrichment, and single color center formation
Publisher: Wiley
Date: 21-10-2015
Atom–Photon Coupling from Nitrogen-vacancy Centres Embedded in Tellurite Microspheres
Publisher: Springer Science and Business Media LLC
Date: 22-06-2015
DOI: 10.1038/SREP11486
Abstract: We have developed a technique for creating high quality tellurite microspheres with embedded nanodiamonds (NDs) containing nitrogen-vacancy (NV) centres. This hybrid method allows fluorescence of the NVs in the NDs to be directly, rather than evanescently, coupled to the whispering gallery modes of the tellurite microspheres at room temperature. As a demonstration of its sensing potential, shifting of the resonance peaks is also demonstrated by coating a sphere surface with a liquid layer. This new approach is a robust way of creating cavities for use in quantum and sensing applications.
Observation of single-ion induced charge collection in diode by a heavy ion microbeam system
Publisher: Elsevier BV
Date: 09-2003
Opportunity of single atom control for quantum processing in silicon and diamond
Publisher: IEEE
Date: 06-2014
Radiation Resistance of Wide Band Gapn+/pAlInGaP Solar Cell for High-Efficient Multijunction Space Solar Cells
Publisher: IOP Publishing
Date: 29-06-2007
DOI: 10.1143/JJAP.46.L645
Single-photon emitting diode in silicon carbide
Publisher: Springer Science and Business Media LLC
Date: 23-07-2015
DOI: 10.1038/NCOMMS8783
Abstract: Electrically driven single-photon emitting devices have immediate applications in quantum cryptography, quantum computation and single-photon metrology. Mature device fabrication protocols and the recent observations of single defect systems with quantum functionalities make silicon carbide an ideal material to build such devices. Here, we demonstrate the fabrication of bright single-photon emitting diodes. The electrically driven emitters display fully polarized output, superior photon statistics (with a count rate of >300 kHz) and stability in both continuous and pulsed modes, all at room temperature. The atomic origin of the single-photon source is proposed. These results provide a foundation for the large scale integration of single-photon sources into a broad range of applications, such as quantum cryptography or linear optics quantum computing.
Characterization of charge generated in silicon carbide n+p diodes using transient ion beam-induced current
Publisher: Elsevier BV
Date: 04-2005
Photoluminescence properties of praseodymium ions implanted into submicron regions in gallium nitride
Publisher: IOP Publishing
Date: 25-04-2019
Nanodiamond-polycaprolactone composite: A new material for tissue engineering with sub-dermal imaging capabilities
Publisher: Elsevier BV
Date: 12-2016
Stimulated emission from nitrogen-vacancy centres in diamond
Publisher: Springer Science and Business Media LLC
Date: 27-01-2017
DOI: 10.1038/NCOMMS14000
Radiation hardness of n-type SiC Schottky barrier diodes irradiated with MeV He ion microbeam
Publisher: Elsevier BV
Date: 04-2015
Photon extraction enhancement of praseodymium ions in gallium nitride nanopillars
Publisher: Springer Science and Business Media LLC
Date: 08-12-2022
DOI: 10.1038/S41598-022-25522-6
Abstract: Lanthanoid-doped Gallium Nitride (GaN) integrated into nanophotonic technologies is a promising candidate for room-temperature quantum photon sources for quantum technology applications. We manufactured praseodymium (Pr)-doped GaN nanopillars of varying size, and showed significantly enhanced room-temperature photon extraction efficiency compared to unstructured Pr-doped GaN. Implanted Pr ions in GaN show two main emission peaks at 650.3 nm and 651.8 nm which are attributed to 3 P 0 - 3 F 2 transition in the 4 f -shell. The maximum observed enhancement ratio was 23.5 for 200 nm diameter circular pillars, which can be ided into the emitted photon extraction enhancement by a factor of 4.5 and the photon collection enhancement by a factor of 5.2. The enhancement mechanism is explained by the eigenmode resonance inside the nanopillar. Our study provides a pathway for Lanthanoid-doped GaN nano/micro-scale photon emitters and quantum technology applications.
Current transient effect in N-channel 6H-SiC MOSFET induced by heavy ion irradiation
Publisher: Trans Tech Publications, Ltd.
Date: 04-2010
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.645-648.1013
Abstract: This paper investigates the transient induced currents by energetic carbon ions in 6H-SiC MOSFETs and the carrier dynamic response due to such a heavy ion collision is simulated by Technology Computer Aided Design (TCAD). It was found that a heavy ion strike induces a bipolar effect on the transistor, whereby the current transients can vary in both polarities. And this has been attributed to the inherent in the MOSFET is a parasitic bipolar junction transistor.
Defect-induced performance degradation of 4H-SiC Schottky barrier diode particle detectors
Publisher: AIP Publishing
Date: 12-04-2013
DOI: 10.1063/1.4801797
Abstract: The formation and evolution of defects in 4H-SiC Schottky barrier diode high-energy particle detectors have been investigated and correlated with the detectors' properties. Low temperature annealing at 300 °C is found to significantly recover the charge collection efficiency as degraded by 1 MeV electron irradiation. At higher temperatures, an anneal-induced degradation in the detector's performance is observed. Current-voltage, capacitance-voltage, and deep level transient spectroscopy (DLTS) measurements are used to ascertain the effect of defects on the detector performance. The latter reveals that the DLTS defect levels, EH1 and EH3, are related to the initial recovery of the charge collection efficiency.
Array of bright silicon-vacancy centers in diamond fabricated by low-energy focused ion beam implantation
Publisher: IOP Publishing
Date: 15-10-2014
Evaluation of the characteristics of silicon carbide diodes using transient-IBIC technique
Publisher: Elsevier BV
Date: 09-2003
Targeting cell surface glycans with lectin-coated fluorescent nanodiamonds
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2NA00036A
Abstract: Nanodiamonds were coated in lectins to target glycan receptors on astrocytes, neurons and microglia. The uptake in each cell type was variable depending on their coating of Aleuria aurantia lectin, wheat germ agglutinin or tomato lectin.
Bright and photostable nitrogen-vacancy fluorescence from unprocessed detonation nanodiamond
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C6NR07834F
Abstract: Bright and photostable fluorescence from nitrogen-vacancy (NV) centers is demonstrated in unprocessed detonation nanodiamond particle aggregates. The optical properties of these particles is analyzed using confocal fluorescence microscopy and spectroscopy, time resolved fluorescence decay measurements, and optically detected magnetic resonance experiments. Two particle populations with distinct optical properties are identified and compared to high-pressure high-temperature (HPHT) fluorescent nanodiamonds. We find that the brightness of one detonation nanodiamond particle population is on the same order as that of highly processed fluorescent 100 nm HPHT nanodiamonds. Our results may open the path to a simple and up-scalable route for the production of fluorescent NV nanodiamonds for use in bioimaging applications.
Nanomechanical Sensing Using Spins in Diamond
Publisher: American Chemical Society (ACS)
Date: 13-02-2017
DOI: 10.1021/ACS.NANOLETT.6B04544
Abstract: Nanomechanical sensors and quantum nanosensors are two rapidly developing technologies that have erse interdisciplinary applications in biological and chemical analysis and microscopy. For ex le, nanomechanical sensors based upon nanoelectromechanical systems (NEMS) have demonstrated chip-scale mass spectrometry capable of detecting single macromolecules, such as proteins. Quantum nanosensors based upon electron spins of negatively charged nitrogen-vacancy (NV) centers in diamond have demonstrated erse modes of nanometrology, including single molecule magnetic resonance spectroscopy. Here, we report the first step toward combining these two complementary technologies in the form of diamond nanomechanical structures containing NV centers. We establish the principles for nanomechanical sensing using such nanospin-mechanical sensors (NSMS) and assess their potential for mass spectrometry and force microscopy. We predict that NSMS are able to provide unprecedented AC force images of cellular biomechanics and to not only detect the mass of a single macromolecule but also image its distribution. When combined with the other nanometrology modes of the NV center, NSMS potentially offer unparalleled analytical power at the nanoscale.
Near Infrared Photoluminescence of N<sub>C</sub>V<sub>Si</sub><sup>-</sup> Centers in High-Purity Semi-Insulating 4H-SiC Irradiated with Energetic Charged Particles
Publisher: Trans Tech Publications, Ltd.
Date: 07-2020
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.1004.355
Abstract: This paper reports optical propertites of negatively charged N C V Si - centers in silicon carbide (a nitrogen substituting for a carbon atom adjacent to a silicon vacancy) whose emission wavlength is 1100-1500 nm at room temperature. High-purity semi-insulating (HPSI) 4H-SiCs are implanted with high energy N ion beams and subsequently thermally annealed to form N C V Si centers. We investigated a wide range of N ion implantation dose using a micro ion beam implantation technique and observed the photoluminescence intensity from the SiC-NV centers. We show that under conditions of heavy implantation, the excitation laser power excites residual defects and their fluorescences intereferes with the emission from the N C V Si - centers. These results allow us to clarify the requirements to optically detect isolated single N C V Si - centers at lightly implanted conditions.
Room Temperature Quantum Emission from Cubic Silicon Carbide Nanoparticles
Publisher: American Chemical Society (ACS)
Date: 24-07-2014
DOI: 10.1021/NN502719Y
Abstract: The photoluminescence (PL) arising from silicon carbide nanoparticles has so far been associated with the quantum confinement effect or to radiative transitions between electronically active surface states. In this work we show that cubic phase silicon carbide nanoparticles with diameters in the range 45-500 nm can host other point defects responsible for photoinduced intrabandgap PL. We demonstrate that these nanoparticles exhibit single photon emission at room temperature with record saturation count rates of 7 × 10(6) counts/s. The realization of nonclassical emission from SiC nanoparticles extends their potential use from fluorescence biomarker beads to optically active quantum elements for next generation quantum sensing and nanophotonics. The single photon emission is related to single isolated SiC defects that give rise to states within the bandgap.
Depth Profile Analysis of Deep Level Defects in 4H-SiC Introduced by Radiation
Publisher: MDPI AG
Date: 22-09-2020
Abstract: Deep level defects created by implantation of light-helium and medium heavy carbon ions in the single ion regime and neutron irradiation in n-type 4H-SiC are characterized by the DLTS technique. Two deep levels with energies 0.4 eV (EH1) and 0.7 eV (EH3) below the conduction band minimum are created in either ion implanted and neutron irradiated material beside carbon vacancies (Z1/2). In our study, we analyze components of EH1 and EH3 deep levels based on their concentration depth profiles, in addition to (−3/=) and (=/−) transition levels of silicon vacancy. A higher EH3 deep level concentration compared to the EH1 deep level concentration and a slight shift of the EH3 concentration depth profile to larger depths indicate that an additional deep level contributes to the DLTS signal of the EH3 deep level, most probably the defect complex involving interstitials. We report on the introduction of metastable M-center by light/medium heavy ion implantation and neutron irradiation, previously reported in cases of proton and electron irradiation. Contribution of M-center to the EH1 concentration profile is presented.
Radiation-resistance analysis of GaAs and InGaP sub cells for InGaP/GaAs/Ge 3-junction space solar cells
Publisher: IEEE
Date: 05-2008
Atom-photon coupling from nitrogen-vacancy centers embedded in tellurite microspheres
Publisher: OSA
Date: 2015
Detection of atomic spin labels in a lipid bilayer using a single-spin nanodiamond probe
Publisher: Proceedings of the National Academy of Sciences
Date: 17-06-2013
Abstract: Magnetic field fluctuations arising from fundamental spins are ubiquitous in nanoscale biology, and are a rich source of information about the processes that generate them. However, the ability to detect the few spins involved without averaging over large ensembles has remained elusive. Here, we demonstrate the detection of gadolinium spin labels in an artificial cell membrane under ambient conditions using a single-spin nanodiamond sensor. Changes in the spin relaxation time of the sensor located in the lipid bilayer were optically detected and found to be sensitive to near-in idual (4 ± 2) proximal gadolinium atomic labels. The detection of such small numbers of spins in a model biological setting, with projected detection times of 1 s [corresponding to a sensitivity of ∼5 Gd spins per Hz 1/2 ], opens a pathway for in situ nanoscale detection of dynamical processes in biology.
Optical properties of neodymium ions in nanoscale regions of gallium nitride
Publisher: Optica Publishing Group
Date: 18-09-2020
DOI: 10.1364/OME.401765
Abstract: Wide bandgap semiconductors are increasingly important for bioimaging applications, as they can possess good biocompatibility and host a large range of fluorescent defects spanning the visible to infrared. Gallium nitride is one promising host for photostable fluorophores. In particular, neodymium (Nd)-doped gallium nitride (GaN) shows bright near-infrared fluorescence and narrow room temperature linewidth and is therefore a candidate material for fluorescent probes for bioimaging. To explore the conditions necessary to generate biomarkers based on Nd:GaN, this paper reports the room temperature photoluminescence (PL) properties of small ensembles of Nd ions implanted into the nanoscale regions of GaN epilayers. The minimum volume of Nd-implanted GaN that can be optically detected in this study is about 8×10 4 nm 3 and the minimum detected ensemble of Nd ions is about 4×10 3 , although not all of implanted Nd ions activate as luminescence centers. We show from the PL excitation spectra that the strongest resonant excitation appears at 619 nm, attributed to the 4 I 9/2 → 4 G 5/2 ( 4 G 7/2 ) transition in the 4 f -shell. We measure the luminescence lifetime to be several tens of microseconds. We also identify the presence of a different excitation mechanism from the resonant excitation when excited below 510 nm (above 2.43 eV).
Magnetic-field-dependent stimulated emission from nitrogen-vacancy centers in diamond
Publisher: American Association for the Advancement of Science (AAAS)
Date: 03-06-2022
Abstract: Negatively charged nitrogen-vacancy (NV) centers in diamond are promising magnetic field quantum sensors. Laser threshold magnetometry theory predicts improved NV center ensemble sensitivity via increased signal strength and magnetic field contrast. Here, we experimentally demonstrate laser threshold magnetometry. We use a macroscopic high-finesse laser cavity containing a highly NV-doped and low absorbing diamond gain medium that is pumped at 532 nm and resonantly seeded at 710 nm. This enables a 64% signal power lification by stimulated emission. We test the magnetic field dependency of the lification and thus demonstrate magnetic field–dependent stimulated emission from an NV center ensemble. This emission shows an ultrahigh contrast of 33% and a maximum output power in the milliwatt regime. The coherent readout of NV centers pave the way for novel cavity and laser applications of quantum defects and diamond NV magnetic field sensors with substantially improved sensitivity for the health, research, and mining sectors.
Engineering the Interface: Nanodiamond Coating on 3D-Printed Titanium Promotes Mammalian Cell Growth and Inhibits Staphylococcus aureus Colonization
Publisher: American Chemical Society (ACS)
Date: 14-06-2019
Abstract: Additively manufactured selective laser melted titanium (SLM-Ti) opens the possibility of tailored medical implants for patients. Despite orthopedic implant advancements, significant problems remain with regard to suboptimal osseointegration at the interface between the implant and the surrounding tissue. Here, we show that applying a nanodiamond (ND) coating onto SLM-Ti scaffolds provides an improved surface for mammalian cell growth while inhibiting colonization of
M-center in 4H-SiC: Isothermal DLTS and first principles modeling studies
Publisher: AIP Publishing
Date: 28-09-2021
DOI: 10.1063/5.0064958
Abstract: We report on a bistable defect known as M-center, here introduced in n-type 4H-SiC by 2 MeV He ion implantation. Deep levels of the M-center are investigated by means of junction spectroscopy techniques, namely, deep level transient spectroscopy (DLTS) and isothermal DLTS. In addition to previously reported three deep levels arising from the M-center (labeled as M1, M2, and M3), we provide direct evidence on the existence of a fourth transition (labeled as M4) with an activation energy of 0.86 eV. Activation energies and apparent capture cross sections for all four metastable defects are determined. From first-principles calculations, it is shown that the observed features of the M-center, including the charge state character, transition levels, bi-stability dynamics, and annealing, are all accounted for by a carbon self-interstitial.
Creation of nitrogen-vacancy centers in chemical vapor deposition diamond for sensing applications
Publisher: IOP Publishing
Date: 03-2022
Abstract: The nitrogen-vacancy (NV) center in diamond is a promising quantum system for magnetometry applications exhibiting optical readout of minute energy shifts in its spin sub-levels. Key material requirements for NV ensembles are a high NV − concentration, a long spin coherence time and a stable charge state. However, these are interdependent and can be difficult to optimize during diamond growth and subsequent NV creation. In this work, we systematically investigate the NV center formation and properties in bulk chemical vapor deposition (CVD) diamond. The nitrogen flow during growth is varied by over four orders of magnitude, resulting in a broad range of single substitutional nitrogen concentrations of 0.2–20 parts per million. For a fixed nitrogen concentration, we optimize electron-irradiation fluences with two different accelerated electron energies, and we study defect formation via optical characterizations. We discuss a general approach to determine the optimal irradiation conditions, for which an enhanced NV concentration and an optimum of NV charge states can both be satisfied. We achieve spin–spin coherence times T 2 ranging from 45.5 to 549 μ s for CVD diamonds containing 168 to 1 parts per billion NV − centers, respectively. This study shows a pathway to engineer properties of NV-doped CVD diamonds for improved sensitivity.
Minority-Carrier Injection-Enhanced Recovery of Radiation-Induced Defects in n+p AlInGaP Solar Cells
Publisher: IEEE
Date: 05-2006
Related Organisations
National Institutes For Quantum And Radiological Science And Technology
Location: Japan
National Institutes For Quantum Science And Technology
Location: Japan
Related Funding Activities
Discovery Projects - Grant ID: DP220102518
Start Date: 11-2022
End Date: 11-2025
Amount: $400,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP220103181
Start Date: 09-2022
End Date: 09-2025
Amount: $670,000.00
Funder: Australian Research Council
View Funded ActivityARC Centres Of Excellence - Grant ID: CE140100003
Start Date: 10-2014
End Date: 12-2020
Amount: $23,000,000.00
Funder: Australian Research Council
View Funded Activity