Yan-Kai Tzeng
Associate Scientist, SLAC National Accelerator Laboratory
All Publications
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Dynamics of Radiation Damage Buildup in Ultrathin Hexagonal Boron Nitride Films under Ion Bombardment.
ACS applied materials & interfaces
2026
Abstract
Two-dimensional hexagonal boron nitride (hBN) is attractive for several emerging applications. Ion bombardment can be used to modify the hBN properties. However, the understanding of radiation damage buildup in hBN remains limited. Here, we investigate the effects of the dose rate and ion mass on radiation damage buildup by studying 40 nm-thick hBN films bombarded at room temperature with 500 keV 4He, 15N, 40Ar, and 129Xe ions and comparing with results for ion bombardment of polycrystalline hBN ceramics. Raman spectroscopy is used to quantify damage buildup, and transmission electron microscopy is used for microstructural analysis. Experiments are complemented by molecular dynamics simulations of the formation and evolution of point defects. Lighter ions are found to be more efficient at disordering hBN than heavier ions. This observation points to a critical role of intracascade defect processes. In contrast, a negligible dose rate effect observed suggests limited intercascade defect dynamic annealing processes for these irradiation conditions. These findings provide a fundamental basis for hBN defect engineering.
View details for DOI 10.1021/acsami.5c25472
View details for PubMedID 42080797
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Feedback, physics, and forecasts: The emerging paradigm of machine learning-driven battery research
MRS ENERGY & SUSTAINABILITY
2026
View details for DOI 10.1557/s43581-026-00153-w
View details for Web of Science ID 001713961600001
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Uniform pore structure enables negligible degradation in undoped and uncoated Ni-rich cathodes
NATURE ENERGY
2026
View details for DOI 10.1038/s41560-026-01988-w
View details for Web of Science ID 001704139000001
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Epitaxial Electrodeposition of Zinc on Different Single Crystal Copper Substrates for High Performance Aqueous Batteries.
Nano letters
2025
Abstract
The aqueous zinc metal battery holds great potential for large-scale energy storage due to its safety, low cost, and high theoretical capacity. However, challenges such as corrosion and dendritic growth necessitate controlled zinc deposition. This study employs epitaxy to achieve large-area, dense, and ultraflat zinc plating on textured copper foil. High-quality copper foils with Cu(100), Cu(110), and Cu(111) facets were prepared and systematically compared. The results show that Cu(111) is the most favorable for zinc deposition, offering the lowest nucleation overpotential, diffusion energy, and interfacial energy with a Coulombic efficiency (CE) of 99.93%. The study sets a record for flat-zinc areal loading at 20 mAh/cm2. These findings provide some clarity on the best-performing copper and zinc crystalline facets, with Cu(111)/Zn(0002) ranking the highest. Using a MnO2-Zn full cell model, the research achieved an exceptional cycle life of over 800 cycles in a cathode-anode-free battery configuration.
View details for DOI 10.1021/acs.nanolett.4c04535
View details for PubMedID 39835735
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Improving the creation of SiV centers in diamond via sub-μs pulsed annealing treatment.
Nature communications
2024; 15 (1): 7251
Abstract
Silicon-vacancy (SiV) centers in diamond are emerging as promising quantum emitters in applications such as quantum communication and quantum information processing. Here, we demonstrate a sub-μs pulsed annealing treatment that dramatically increases the photoluminescence of SiV centers in diamond. Using a silane-functionalized adamantane precursor and a laser-heated diamond anvil cell, the temperature and energy conditions required to form SiV centers in diamond were mapped out via an optical thermometry system with an accuracy of ±50 K and a 1 μs temporal resolution. Annealing scheme studies reveal that pulsed annealing can obviously minimize the migration of SiV centers out of the diamond lattice, and a 2.5-fold increase in the number of emitting centers was achieved using a series of 200-ns pulses at a 50 kHz repetition rate via acousto-optic modulation. Our study provides a novel pulsed annealing treatment approach to improve the efficiency of the creation of SiV centers in diamond.
View details for DOI 10.1038/s41467-024-51523-2
View details for PubMedID 39179592
View details for PubMedCentralID 7097076
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Cesium-mediated electron redistribution and electron-electron interaction in high-pressure metallic CsPbI3.
Nature communications
2022; 13 (1): 7067
Abstract
Electron-phonon coupling was believed to govern the carrier transport in halide perovskites and related phases. Here we demonstrate that electron-electron interaction enhanced by Cs-involved electron redistribution plays a direct and prominent role in the low-temperature electrical transport of compressed CsPbI3 and renders Fermi liquid (FL)-like behavior. By compressing delta-CsPbI3 to 80GPa, an insulator-semimetal-metal transition occurs, concomitant with the completion of a slow structural transition from the one-dimensional Pnma (delta) phase to a three-dimensional Pmn21 (epsilon) phase. Deviation from FL behavior is observed upon CsPbI3 entering the metallic epsilon phase, which progressively evolves into a FL-like state at 186GPa. First-principles density functional theory calculations reveal that the enhanced electron-electron coupling results from the sudden increase of the 5d state occupation in Cs and I atoms. Our study presents a promising strategy of cationic manipulation for tuning the electronic structure and carrier scattering of halide perovskites at high pressure.
View details for DOI 10.1038/s41467-022-34786-5
View details for PubMedID 36400789
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Atmospheric-Pressure Flame Vapor Deposition of Nanocrystalline Diamonds: Implications for Scalable and Cost-Effective Coatings
ACS APPLIED NANO MATERIALS
2022
View details for DOI 10.1021/acsanm.2c02059
View details for Web of Science ID 000885759500001
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Synthesis of Atomically Thin Hexagonal Diamond with Compression.
Nano letters
2020
Abstract
Atomically thin diamond, also called diamane, is a two-dimensional carbon allotrope and has attracted considerable scientific interest because of its potential physical properties. However, the successful synthesis of a pristine diamane has up until now not been achieved. We demonstrate the realization of a pristine diamane through diamondization of mechanically exfoliated few-layer graphene via compression. Resistance, optical absorption, and X-ray diffraction measurements reveal that hexagonal diamane (h-diamane) with a bandgap of 2.8 ± 0.3 eV forms by compressing trilayer and thicker graphene to above 20 GPa at room temperature and can be preserved upon decompression to 1.0 GPa. Theoretical calculations indicate that a (-2110)-oriented h-diamane is energetically stable and has a lower enthalpy than its few-layer graphene precursor above the transition pressure. Compared to gapless graphene, semiconducting h-diamane offers exciting possibilities for carbon-based electronic devices.
View details for DOI 10.1021/acs.nanolett.0c01872
View details for PubMedID 32578991
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Tapered ultra-high numerical aperture optical fiber tip for nitrogen vacancy ensembles based endoscope in a fluidic environment
APPLIED PHYSICS LETTERS
2020; 116 (11)
View details for DOI 10.1063/1.5140785
View details for Web of Science ID 000521259000001
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Synergistic enhancement of electrocatalytic CO2 reduction to C2 oxygenates at nitrogen-doped nanodiamonds/Cu interface.
Nature nanotechnology
2020
Abstract
To date, effective control over the electrochemical reduction of CO2 to multicarbon products (C≥2) has been very challenging. Here, we report a design principle for the creation of a selective yet robust catalytic interface for heterogeneous electrocatalysts in the reduction of CO2 to C2 oxygenates, demonstrated by rational tuning of an assembly of nitrogen-doped nanodiamonds and copper nanoparticles. The catalyst exhibits a Faradaic efficiency of ~63% towards C2 oxygenates at applied potentials of only -0.5V versus reversible hydrogen electrode. Moreover, this catalyst shows an unprecedented persistent catalytic performance up to 120h, with steady current and only 19% activity decay. Density functional theory calculations show that CO binding is strengthened at the copper/nanodiamond interface, suppressing CO desorption and promoting C2 production by lowering the apparent barrier for CO dimerization. The inherent compositional and electronic tunability of the catalyst assembly offers an unrivalled degree of control over the catalytic interface, and thereby the reaction energetics and kinetics.
View details for DOI 10.1038/s41565-019-0603-y
View details for PubMedID 31907442
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Nanodiamond Integration with Photonic Devices
LASER & PHOTONICS REVIEWS
2019
View details for DOI 10.1002/lpor.201800316
View details for Web of Science ID 000480009200001
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Laser-induced heating in a high-density ensemble of nitrogen-vacancy centers in diamond and its effects on quantum sensing
OPTICS LETTERS
2019; 44 (11): 2851–54
View details for DOI 10.1364/OL.44.002851
View details for Web of Science ID 000469838100061
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Frequency Tunable Single-Photon Emission From a Single Atomic Defect in a Solid
IEEE. 2019
View details for Web of Science ID 000482226303114
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Cavity-Enhanced Raman Emission from a Single Color Center in a Solid.
Physical review letters
2018; 121 (8): 083601
Abstract
We demonstrate cavity-enhanced Raman emission from a single atomic defect in a solid. Our platform is a single silicon-vacancy center in diamond coupled with a monolithic diamond photonic crystal cavity. The cavity enables an unprecedented frequency tuning range of the Raman emission (100GHz) that significantly exceeds the spectral inhomogeneity of silicon-vacancy centers in diamond nanostructures. We also show that the cavity selectively suppresses the phonon-induced spontaneous emission that degrades the efficiency of Raman photon generation. Our results pave the way towards photon-mediated many-body interactions between solid-state quantum emitters in a nanophotonic platform.
View details for PubMedID 30192607
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Cavity-Enhanced Raman Emission from a Single Color Center in a Solid
PHYSICAL REVIEW LETTERS
2018; 121 (8)
View details for DOI 10.1103/PhysRevLett.121.083601
View details for Web of Science ID 000442348000005
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An Ultrastrong Double-Layer Nanodiamond Interface for Stable Lithium Metal Anodes
JOULE
2018; 2 (8): 1595–1609
View details for DOI 10.1016/j.joule.2018.05.007
View details for Web of Science ID 000441627400022
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Enhancing fluorescence excitation and collection from the nitrogen-vacancy center in diamond through a micro-concave mirror
APPLIED PHYSICS LETTERS
2018; 113 (4)
View details for DOI 10.1063/1.5037807
View details for Web of Science ID 000440046600007
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Strongly Cavity-Enhanced Spontaneous Emission from Silicon-Vacancy Centers in Diamond
NANO LETTERS
2018; 18 (2): 1360–65
Abstract
Quantum emitters are an integral component for a broad range of quantum technologies, including quantum communication, quantum repeaters, and linear optical quantum computation. Solid-state color centers are promising candidates for scalable quantum optics due to their long coherence time and small inhomogeneous broadening. However, once excited, color centers often decay through phonon-assisted processes, limiting the efficiency of single-photon generation and photon-mediated entanglement generation. Herein, we demonstrate strong enhancement of spontaneous emission rate of a single silicon-vacancy center in diamond embedded within a monolithic optical cavity, reaching a regime in which the excited-state lifetime is dominated by spontaneous emission into the cavity mode. We observe 10-fold lifetime reduction and 42-fold enhancement in emission intensity when the cavity is tuned into resonance with the optical transition of a single silicon-vacancy center, corresponding to 90% of the excited-state energy decay occurring through spontaneous emission into the cavity mode. We also demonstrate the largest coupling strength (g/2π = 4.9 ± 0.3 GHz) and cooperativity (C = 1.4) to date for color-center-based cavity quantum electrodynamics systems, bringing the system closer to the strong coupling regime.
View details for DOI 10.1021/acs.nanolett.7b05075
View details for Web of Science ID 000425559700102
View details for PubMedID 29377701
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Optimized photonics: from on-chip nonclassical light sources to circuits
IEEE. 2018
View details for Web of Science ID 000526031003464
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Diamond Color Center Integration with a Silicon Carbide Photonics Platform
IEEE. 2018
View details for Web of Science ID 000526031001352
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Strong Cavity Enhancement of Spontaneous Emission from Silicon-Vacancy Centers in Diamond
IEEE. 2018
View details for Web of Science ID 000526031001068
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Vertical-Substrate MPCVD Epitaxial Nanodiamond Growth.
Nano letters
2017
Abstract
Color center-containing nanodiamonds have many applications in quantum technologies and biology. Diamondoids, molecular-sized diamonds have been used as seeds in chemical vapor deposition (CVD) growth. However, optimizing growth conditions to produce high crystal quality nanodiamonds with color centers requires varying growth conditions that often leads to ad-hoc and time-consuming, one-at-a-time testing of reaction conditions. In order to rapidly explore parameter space, we developed a microwave plasma CVD technique using a vertical, rather than horizontally oriented stage-substrate geometry. With this configuration, temperature, plasma density, and atomic hydrogen density vary continuously along the vertical axis of the substrate. This variation allowed rapid identification of growth parameters that yield single crystal diamonds down to 10 nm in size and 75 nm diameter optically active center silicon-vacancy (Si-V) nanoparticles. Furthermore, this method may provide a means of incorporating a wide variety of dopants in nanodiamonds without ion irradiation damage.
View details for DOI 10.1021/acs.nanolett.6b04543
View details for PubMedID 28182433
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Complete Coherent Control of Silicon-Vacancies in Diamond Nanopillars Containing Single Defect Centers
IEEE. 2017
View details for Web of Science ID 000427296200411
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Complete coherent control of silicon vacancies in diamond nanopillars containing single defect centers
OPTICA
2017; 4 (11): 1317-1321
View details for DOI 10.1364/OPTICA.4.001317
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Emitter-Cavity Coupling in Hybrid Silicon Carbide-Nanodiamond Microdisk Resonators
IEEE. 2016
View details for Web of Science ID 000391286402328