Enhanced UV Light emission from Silicon nanoparticles induced by Au ion implantation

利用多层电子叠层成像定量表征注入诱导损伤与点缺陷

Quantifying Implantation Induced Damage and Point Defects with Multislice Electron Ptychography

研究利用多层电子叠层成像定量 Er 注入 4H-SiC 的晶体损伤，结合模拟揭示静态位移对点缺陷检测的限制，并实现深部硅空位及局部应变测量。

The effect of low-energy ion-implantation on the electrical transport properties of Si-SiO2 MOSFETs

Using silicon MOSFETs with thin (5nm) thermally grown SiO2 gate dielectrics, we characterize the density of electrically active traps at low-temperature after 16keV phosphorus ion-implantation through the oxide. We find that, after rapid thermal annealing at 1000oC for 5 seconds, each implanted P ion contributes an additional 0.08 plus/minus 0.03 electrically active traps, whilst no increase in the number of traps is seen for comparable silicon implants. This result shows that the additional traps are ionized P donors, and not damage due to the implantation process. We also find, using the roo…

Fabrication of silicon nanocrystals using sequential Au ion implantation

Silicon nanocrystals are produced using a two-stage gold ion implantation technique. First stage implantation using low energy ions leads to the formation of an amorphous Si (a-Si) layer. A subsequent high energy Au irradiation in the second stage is found to produce strained Si NCs. An annealing at a temperature as low as 500$^o$C is seen to result in strain free NCs showing quantum confinement effects. Higher temperature annealing of the samples is found to result in growth in size from recrystallization of the a-Si matrix. Raman Scattering, X-ray diffraction (XRD) and Rutherford Backscatter…

Deep level transient spectroscopy study for the development of ion-implanted silicon field-effect transistors for spin-dependent transport

A deep level transient spectroscopy (DLTS) study of defects created by low-fluence, low-energy ion implantation for development of ion-implanted silicon field-effect transistors for spin-dependent transport experiments is presented. Standard annealing strategies are considered to activate the implanted dopants and repair the implantation damage in test metal-oxide-semiconductor (MOS) capacitors. Fixed oxide charge, interface trapped charge and the role of minority carriers in DLTS are investigated. A furnace anneal at 950 $\rm ^{o}$C was found to activate the dopants but did not repair the imp…

Modification of low-temperature silicon dioxide films under the influence of technology factors

The structure, composition and electrophysical characteristics of low-temperature silicon dioxide films under influence of various technology factors, such as ion implantation, laser irradiation, thermal and photonic annealing, have been studied. Silicon dioxide films have been obtained by monosilane oxidation using plasma chemical method, reactive cathode sputtering, and tetraethoxysilane pyrolysis. In the capacity of substrates, germanium, silicon, gallium arsenide and gallium nitride were used. Structure and composition of the dielectric films were analyzed by methods of infrared transmissi…

The effects of ion implantation damage to photonic crystal optomechanical resonators in silicon

Optomechanical resonators were fabricated on a silicon-on-insulator (SOI) substrate that had been implanted with phosphorus donors. The resonators' mechanical and optical properties were then measured (at 6 kelvin and room temperature) before and after the substrate was annealed. All measured resonators survived the annealing and their mechanical linewidths decreased while their optical and mechanical frequencies increased. This is consistent with crystal lattice damage from the ion implantation causing the optical and mechanical properties to degrade and then subsequently being repaired by th…

Isotopic enrichment of silicon by high fluence $^{28}$Si$^-$ ion implantation

Spins in the `semiconductor vacuum' of silicon-28 ($^{28}$Si) are suitable qubit candidates due to their long coherence times. An isotopically purified substrate of $^{28}$Si is required to limit the decoherence pathway caused by magnetic perturbations from surrounding $^{29}$Si nuclear spins (I=1/2), present in natural Si (nat Si) at an abundance of 4.67%. We isotopically enrich surface layers of nat Si by sputtering using high fluence $^{28}$Si$^-$ implantation. Phosphorus (P) donors implanted into one such $^{28}$Si layer with ~3000 ppm $^{29}$Si, produced by implanting 30 keV $^{28}$Si$^-$…

Environmentally friendly method of silicon recycling: synthesis of silica nanoparticles in an aqueous solution

Future decades will experience tons of silicon waste from various sources, with no reliable recycling route. The transformation of bulk silicon into SiO2 nanoparticles is environmentally significant because it provides a way to recycle residual silicon waste. To address the needs of silicon recycling, we develop a top-down approach that achieves 100% conversion of bulk silicon to silica nanoparticles with outcome sizes of 8-50 nm. In addition to upcycling the potential of silica, our method also possesses several advantages, such as simplicity, scalability and controllable particle size distri…

非晶硅中的自离子注入与结构弛豫

Self-ion implantation and structural relaxation in amorphous silicon

本文利用FEM研究自离子注入非晶硅的热弛豫，揭示MRO先增强后减弱并最终再结晶，支持PC模型并解释高剂量缺陷与低温放热。

Magneto-optical characterization of MnxGe1-x alloys obtained by ion implantation

Magneto-optical Kerr effect hysteresis loops at various wavelengths in the visible/near-infrared range have been used to characterize the magnetic properties of alloys obtained by implanting Mn ions at fixed energy in a Ge matrix. The details of the hysteresis loops reveal the presence of multiple magnetic contributions. They may be attributed to the inhomogeneous distribution of the magnetic atoms and, in particular, to the known coexistence of diluted Mn in the Ge matrix and metallic Mn-rich nanoparticles embedded in it [Phys. Rev. B 73, 195207(2006)].

Simulation of phosphorus implantation into silicon with a single-parameter electronic stopping power model

We simulate dopant profiles for phosphorus implantation into silicon using a new model for electronic stopping power. In this model, the electronic stopping power is factorized into a globally averaged effective charge Z1*, and a local charge density dependent electronic stopping power for a proton. There is only a single adjustable parameter in the model, namely the one electron radius rs0 which controls Z1*. By fine tuning this parameter, we obtain excellent agreement between simulated dopant profiles and the SIMS data over a wide range of energies for the channeling case. Our work provides …

通过Ga离子注入形成W硅发射中心的分子动力学模拟

Molecular dynamics simulation of W Silicon Emitting Centers formation by Ga ion implantation

本文利用分子动力学模拟研究Ga离子注入与退火后纯硅中W中心的形成，提出三间隙团簇识别方法，发现高能注入增加团簇数量，退火可消除多余缺陷并保留W中心候选缺陷。

Vibrations of free and embedded anisotropic elastic spheres: Application to low-frequency Raman scattering of silicon nanoparticles in silica

Vibrational mode frequencies and damping are calculated for an elastic sphere embedded in an infinite, homogeneous, isotropic elastic medium. Anisotropic elasticity of the sphere significantly shifts the frequencies in comparison to simplified calculations that assume isotropy. New low frequency Raman light scattering data are presented for silicon spheres grown in a SiO2 glass matrix. Principal features of the Raman spectrum are not correctly described by a simple model of the nanoparticle as a free, isotropic sphere, but require both matrix effects and the anisotropy of the silicon to be tak…

硅自旋真空：同位素富集的$^{28}$硅-绝缘体上硅和超高注量离子注入制备的$^{28}$硅

A silicon spin vacuum: isotopically enriched $^{28}$silicon-on-insulator and $^{28}$silicon from ultra-high fluence ion implantation

本研究应用超高注量28Si离子注入制备同位素富集的28Si及28Si-绝缘体上硅样品，将29Si耗尽至7 ppm，厚度至少100 nm，并通过改进模型预测更低耗尽，且退火后无开体积缺陷。

Laser-Doping of Crystalline Silicon Substrates using Doped Silicon Nanoparticles

Crystalline Si substrates are doped by laser annealing of solution processed Si. For this experiment, dispersions of highly B-doped Si nanoparticles (NPs) are deposited onto intrinsic Si and laser processed using an 807.5nm cw-laser. During laser processing the particles as well as a surface-near substrate layer are melted to subsequently crystallize in the same orientation as the substrate. The doping profile is investigated by secondary ion mass spectroscopy revealing a constant B concentration of 2x10^18 cm^-3 throughout the entire analyzed depth of 5μm. Four-point probe measurements demons…

Vibrational density of states of silicon nanoparticles

The vibrational density of states of silicon nanoparticles in the range from 2.3 to 10.3 nm is studied with the help of molecular-dynamics simulations. From these simulations the vibrational density of states and frequencies of bulk-like vibrational modes at high-symmetry points of the Brillouin-zone have been derived. The results show an increase of the density of states at low frequencies and a transfer of modes from the high-frequency end of the spectrum to the intermediate range. At the same time the peak of transverse optical modes is shifted to higher frequencies. These observations are …

Si3N4 single-crystal nanowires grown from silicon micro and nanoparticles near the threshold of passive oxidation

A simple and most promising oxide-assisted catalyst-free method is used to prepare silicon nitride nanowires that give rise to high yield in a short time. After a brief analysis of the state of the art, we reveal the crucial role played by the oxygen partial pressure: when oxygen partial pressure is slightly below the threshold of passive oxidation, a high yield inhibiting the formation of any silica layer covering the nanowires occurs and thanks to the synthesis temperature one can control nanowire dimensions.

Dielectric layer dependent surface plasmon effect of metallic nanoparticles on silicon substrate

The electromagnetic interaction between Ag nanoparticles on the top of the Si substrate and the incident light has been studied by numerical simulations. It is found that the presence of a dielectric layer with different thickness leads to varied resonance wavelength and scattering cross section, and consequently shifted photocurrent response over all wavelengths. These different behaviors are determined by whether the dielectric layer is beyond the domain where the near field of nanoparticles takes effect, and geometrical optics effects must be taken into account. It is revealed that for part…

Magnetic Mn5Ge3 nanocrystals embedded in crystalline Ge: a magnet/semiconductor hybrid synthesized by ion implantation

The integration of ferromagnetic Mn5Ge3 with the Ge matrix is promising for spin injection in a silicon-compatible geometry. In this paper, we report the preparation of magnetic Mn5Ge3 nanocrystals embedded inside the Ge matrix by Mn ions implantation at elevated temperature. By X-ray diffraction and transmission electron microscopy, we observe crystalline Mn5Ge3 with variable size depending on the Mn ion fluence. The electronic structure of Mn in Mn5Ge3 nanocrystals is 3d6 configuration, the same as in bulk Mn5Ge3. A large positive magnetoresistance has been observed at low temperatures. It c…

通过碳离子注入硅合成的6H-SiC层的结构、电子和光学性质

Structural, electronic, and optical properties of 6H-SiC layers synthesized by implantation of carbon ions into silicon

通过碳离子注入硅并在高剂量下合成高质量6H-SiC薄膜，研究了其结构、电子和光学性质，发现过量碳形成少量氧化碳纳米结构但不影响光学性能。

Spin-dependent recombination at arsenic donors in ion-implanted silicon

Spin-dependent transport processes in thin near-surface doping regions created by low energy ion implantation of arsenic in silicon are detected by two methods, spin-dependent recombination (SDR) using microwave photoconductivity and electrically detected magnetic resonance (EDMR) monitoring the DC current through the sample. The high sensitivity of these techniques allows the observation of the magnetic resonance in particular of As in weak magnetic fields and at low resonance frequencies (40-1200 MHz), where high-field-forbidden transitions between the magnetic substates can be observed due …

Impact of Surface Chemistry of Silicon Nanoparticles on the Structural and Electrochemical Properties of Si/Ni3.4Sn4 Com-posite Anode for Li-Ion Batteries

Embedding silicon nanoparticles in an intermetallic matrix is a promising strategy to produce remarkable bulk anode materials for lithium-ion (Li-ion) batteries with low potential, high electrochemical capacity and good cycling stability. These composite materials can be synthetized at a large scale using mechanical milling. However, for Si-Ni3Sn4 composites, milling also induces a chemical reaction between the two components leading to the formation of free Sn and NiSi2, which is detrimental to the performance of the electrode. To prevent this reaction, a modification of the surface chemistry…

通过局域聚焦离子束注入实现高丰度$^{28}\mathrm{Si}$富集硅

Highly ${ }^{28} \mathrm{Si}$ Enriched Silicon by Localised Focused Ion Beam Implantation

针对天然硅中29Si同位素限制量子比特相干时间的问题，本研究采用45keV 28Si聚焦离子束局域注入法，实现低残余29Si的高丰度富集硅，经退火再结晶后可为大规模硅基量子器件制备提供简便方案。

Induced spin-orbit coupling in silicon thin films by bismuth doping

We demonstrate an enhancement of the spin-orbit coupling in silicon (Si) thin films by doping with bismuth (Bi), a heavy metal, using ion implantation. Quantum corrections to conductance at low temperature in phosphorous-doped Si before and after Bi implantation is measured to probe the increase of the spin-orbit coupling, and a clear modification of magnetoconductance signals is observed: Bi doping changes magnetoconductance from weak localization to the crossover between weak localization and weak antilocalization. The elastic diffusion length, phase coherence length and spin-orbit coupling …

Drain current modulation in a nanoscale field-effect-transistor channel by single dopant implantation

We demonstrate single dopant implantation into the channel of a silicon nanoscale metal-oxide-semiconductor field-effect-transistor. This is achieved by monitoring the drain current modulation during ion irradiation. Deterministic doping is crucial for overcoming dopant number variability in present nanoscale devices and for exploiting single atom degrees of freedom. The two main ion stopping processes that induce drain current modulation are examined. We employ 500~keV He ions, in which electronic stopping is dominant, leading to discrete increases in drain current and 14~keV P dopants for wh…

Position-controlled functionalization of vacancies in silicon by single-ion implanted germanium atoms

Special point defects in semiconductors have been envisioned as suitable components for quantum-information technology. The identification of new deep centers in silicon that can be easily activated and controlled is a main target of the research in the field. Vacancy-related complexes are suitable to provide deep electronic levels but they are hard to control spatially. With the spirit of investigating solid state devices with intentional vacancy-related defects at controlled position, here we report on the functionalization of silicon vacancies by implanting Ge atoms through single-ion impla…

A phenomenological electronic stopping power model for molecular dynamics and Monte Carlo simulation of ion implantation into silicon

It is crucial to have a good phenomenological model of electronic stopping power for modeling the physics of ion implantation into crystalline silicon. In the spirit of the Brandt-Kitagawa effective charge theory, we develop a model for electronic stopping power for an ion, which can be factorized into (i) a globally averaged effective charge taking into account effects of close and distant collisions by target electrons with the ion, and (ii) a local charge density dependent electronic stopping power for a proton. This phenomenological model is implemented into both molecular dynamics and Mon…

碳化硅纳米颗粒的硫醇化与聚乙二醇化

Thiolation and PEGylation of silicon carbide nanoparticle

本文通过在碳化硅纳米颗粒表面引入硫醇封端并偶联PEG分子，制备出兼具荧光特性与生物惰性的超小探针，为开发室温量子传感器生物制剂奠定基础。

Modeling of the transient interstitial diffusion of implanted atoms during low-temperature annealing of silicon substrates

It has been shown that many of the phenomena related to the formation of "tails" in the low-concentration region of ion-implanted impurity distribution are due to the anomalous diffusion of nonequilibrium impurity interstitials. These phenomena include boron implantation in preamorphized silicon, a "hot" implantation of indium ions, annealing of ion-implanted layers et cetera. In particular, to verify this microscopic mechanism, a simulation of boron redistribution during low-temperature annealing of ion-implanted layers has been carried out under different conditions of transient enhanced dif…

Silicon nanostructures toxicity. An ab inito approach

Silicon nanoparticles are widely used in the medical area and until now they have not manifested toxicological effects in humans beings. In order to understand the physical properties that determine their low-toxicity, we perform ab initio computational simulations of silicon nanoclusters, pure, p-doped and hollow structured. The topological and electronic properties obtained pointed out to the number of dangling bonds and electronic density as fundamental parameters to locate active sites and directly related to toxicity, besides the size and surface chemistry of the silicon nanoparticle.

硅纳米颗粒在激光诱导前向转移印刷中的分子动力学模拟

Molecular dynamics simulation of silicon nanoparticle crystallization during laser-induced forward transfer printing

本研究通过分子动力学模拟揭示了LIFT印刷中硅纳米颗粒结晶过程，发现纳米限制可诱导单晶结构形成，为单晶器件制造提供理论支持。

Phonon Confinement in Stressed Silicon Nanocluster

Confined acoustic and optical phonons in Si nanoclusters embedded in sapphire, synthesized using ion-beam implantation are investigated using Raman spectroscopy. The l = 0 and l = 2 confined acoustic phonons, found at low Raman shift, are analyzed using complex frequency model and the size of the nanoparticles are estimated as 4 and 6 nm. For the confined optical phonon, in contrast to expected red shift, the Raman line shape shows a substantial blue shift, which is attributed to size dependent compressive stress in the nanoparticles. The calculated Raman line shape for the stressed nanopartic…

Raman spectroscopy of ion irradiated SiC: chemical defects, strain, annealing, and oxidation

Raman spectroscopy has been used to identify defective bonding in neon and silicon ion irradiated single crystals of 6H-SiC. Observable differences exist in the C-C bonding region corresponding to different defect structures for neon and silicon ion implantations. Raman spectra of ion irradiated SiC show less tensile strain than neutron irradiations, explained by a residual compressive stress caused by the swelling constrained by the undamaged substrate. Evidence of oxidation during high temperature ion implantation is observed as C-O and Si-O Raman signals. Annealing irradiated SiC while acqu…

Hyperpolarized Long-T1 Silicon Nanoparticles for Magnetic Resonance Imaging

Silicon nanoparticles are experimentally investigated as a potential hyperpolarized, targetable MRI imaging agent. Nuclear T_1 times at room temperature for a variety of Si nanoparticles are found to be remarkably long (10^2 to 10^4 s) - roughly consistent with predictions of a core-shell diffusion model - allowing them to be transported, administered and imaged on practical time scales without significant loss of polarization. We also report surface functionalization of Si nanoparticles, comparable to approaches used in other biologically targeted nanoparticle systems.

Synthesis of Long-T1 Silicon Nanoparticles for Hyperpolarized 29Si Magnetic Resonance Imaging

We describe the synthesis, materials characterization and dynamic nuclear polarization (DNP) of amorphous and crystalline silicon nanoparticles for use as hyperpolarized magnetic resonance imaging (MRI) agents. The particles were synthesized by means of a metathesis reaction between sodium silicide (Na4Si4) and silicon tetrachloride (SiCl4) and were surface functionalized with a variety of passivating ligands. The synthesis scheme results in particles of diameter ~10 nm with long size-adjusted 29Si spin lattice relaxation (T1) times (> 600 s), which are retained after hyperpolarization by low …

可逆纳米孔密封与薄硅氮化物膜原位铁氧化物纳米粒子合成

Reversible nanopore sealing and in situ iron oxide nanoparticle synthesis on thin silicon nitride membranes

该研究通过化学反应在硅氮化物纳米孔内原位合成铁氧化物粒子，实现了纳米孔的可逆密封与恢复，为生物传感、等离子体和光子学应用提供了新型纳米粒子-纳米孔芯片技术。

From nanoparticles to nanocrystalline bulk: Field assisted sintering of silicon nanoparticles

Nanocrystalline bulk materials are desirable for many applications as they combine mechanical strength and specific electronic transport properties. Our bottom up approach starts with tailored nanoparticles. Compaction and thermal treatment are crucial, but usually the final stage sintering is accompanied by rapid grain growth which spoils nanocristallinity. For electrically conducting nanoparticles, field activated sintering techniques overcome this problem. Small grain sizes have been maintained in spite of consolidation. Nevertheless, the underlying principles, which are of high practical i…

通过薄SiO2层增强硅中单离子注入的二次电子检测

Enhanced Secondary Electron Detection of Single Ion Implants in Silicon Through Thin SiO2 Layers

本研究提出一种利用二次电子在FIB系统中非破坏性检测单离子注入的方法，通过SiO2覆盖层增强产额，实现98%检测效率和30nm分辨率，为量子器件供体放置提供可扩展途径。

Critical issues in the formation of quantum computer test structures by ion implantation

The formation of quantum computer test structures in silicon by ion implantation enables the characterization of spin readout mechanisms with ensembles of dopant atoms and the development of single atom devices. We briefly review recent results in the characterization of spin dependent transport and single ion doping and then discuss the diffusion and segregation behaviour of phosphorus, antimony and bismuth ions from low fluence, low energy implantations as characterized through depth profiling by secondary ion mass spectrometry (SIMS). Both phosphorus and bismuth are found to segregate to th…

Pulsed laser deposition of the doped lanthanum vanadate nanoparticles on glass and silicon substrates

Thin films from the lanthanum vanadate nanoparticles were successfully grown by pulsed laser deposition method on glass and silicon substrates for the first time. Morphology and thickness of the films depend on a type of substrate and a number of pulses. The films are of 27 to 220 nm thickness and formed by very small particles up to 20 nm and also can contain single nanoparticles with dimensions 40 to 60 nm and sometimes agglomerates of nanoparticles. Spectral properties of the samples have been investigated and discussed. The vanadate films deposited on the silicon substrates lead to appeara…

Ion Beam Synthesis of embedded SiC

The synthesis of embedded silicon carbide was carried out in N type silicon samples having (100) and (111) orientations using high dose implantation of carbon ions at room temperature. The variation of dose was employed to get dose dependence of silicon carbide formation. Postimplant annealing at 1000 C in order to anneal out the implantion induced defects and to get silicon carbide precipitates in silicon matrix. Detailed Fourier tarnsform infrared spectroscopy analysis and x-ray diffraction studies confirms the formation of cubic phase of silicon carbide. The grain size of the silicon carbid…

Ion implantation in nanodiamonds: size effect and energy dependence

Nanoparticles are ubiquitous in nature and are increasingly important for technology. They are subject to bombardment by ionizing radiation in a diverse range of environments. In particular, nanodiamonds represent a variety of nanoparticles of significant fundamental and applied interest. Here we present a combined experimental and computational study of the behaviour of nanodiamonds under irradiation by xenon ions. Unexpectedly, we observed a pronounced size effect on the radiation resistance of the nanodiamonds: particles larger than 8 nm behave similarly to macroscopic diamond (i.e. charact…

Two-Path Phonon-Interference Resonance Induces a Stop Band in Silicon Crystal Matrix by Embedded Nanoparticles Array

In this work, we report a new stop-band formation mechanism by performing the atomistic Green's function calculation and the wave-packet molecular dynamics simulation for a system with germanium-nanoparticle array embedded in a crystalline silicon matrix. When only a single nanoparticle is embedded, the local resonance, induced through destructive interference between two different phonon wave paths, gives rise to several sharp and significant transmittance dips. On the other hand, when the number of embedded nanoparticles further increases to ten, a stop band with complete phonon reflection i…

Optical Activity at 1.55 micron in Si:Er:O Deposited Films

Silicon films doped with Er and O were prepared by techniques of physical vapor deposition on crystalline silicon, ion beam mixing and oxygen incorporation through Ar+ and O2+ implantation, and thermal annealing. Processing steps were tailored to be compatible with standard CMOS and to be of notably low cost to fabricate optically active media for silicon-based infrared emitters. The Si:Er:O films exhibit strong photoluminescence at room temperature that is analogous to Stark-split Er+3 ion 1.55-micron bands in fiber-optic materials. Concentration distributions were determined by Rutherford ba…

Kinetic study of the oxide-assisted catalyst-free synthesis of silicon nitride nanowires

The synthesis of Si3N4 nanowires from the reaction of silicon nanoparticles with N2 in the 1200-1440 C temperature range is reported. The nitridation conditions are such that the reaction with nitrogen is favoured by the presence of silicon oxide in the particles and by the active oxidation of silicon without a catalyst. It is shown that the Si to Si3N4 conversion rate depends on the amount of silicon particles used in the experiments and that, in general, the reaction slows down for greater amounts. This trend is explained by particle stacking, which restricts the exchange of gases between th…

Dopant-enhanced solid phase epitaxy in buried amorphous silicon layers

The kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) are stud- ied in buried amorphous Si (a-Si) layers in which SPE is not retarded by H. As, P, B and Al profiles were formed by multiple energy ion implantation over a con- centration range of 1 - 30 x 1019 /cm3. Anneals were performed in air over the temperature range 460-660 oC and the rate of interface motion was monitored us- ing time resolved reflectivity. The dopant-enhanced SPE rates were modeled with the generalized Fermi level shifting model using degenerate semiconductor statis- tics. The effect of band bending bet…

非晶化介导的 Si-I 到 Si-V 相变及硅纳米颗粒中非晶-Si-V 相可逆相存储

Amorphization-Mediated Si-I to Si-V Phase Transition and Reversible Amorphous-Si-V Phase Memory in Silicon Nanoparticles

本研究通过分子动力学模拟揭示了 10 nm 硅纳米颗粒在三轴压缩下由应力三轴度驱动的两步 Si-I 到 Si-V 相变路径，并发现卸载后非晶-Si-V 间的可逆转变，证明了纳米尺度相存储效应。

On-demand Plasmon Nanoparticle-Embedded Laser-Induced Periodic Surface Structures (LIPSSs) on Silicon for Optical Nanosensing

Ultrashort laser pulses allows to deliver electromagnetic energy to matter causing its localized heating that can be used for both material removal via ablation/evaporation and drive interface chemical reactions. Here, we showed that both mentioned processes can be simultaneously combined within straightforward laser nanotexturing of Si wafer in functionalizing solution to produce a practically relevant metal-semiconductor surface nano-morphology. Such unique hybrid morphology represent deep-subwavelength Si LIPSSs with a extremely short period down to 70 nm with their high-aspect-ratio nanotr…

Optical properties of silicon nanoparticles in the presence of water: A first principles theoretical analysis

We investigate the impact of water, a polar solvent, on the optical absorption of prototypical silicon clusters with oxygen passivation. We approach this complex problem by assessing the contributions of three factors: chemical reactivity; thermal equilibration and dielectric screening. We find that the silanone (Si=O) functional group is not chemically stable in the presence of water and exclude this as a source of significant red shift in absorption in aqueous environments. We perform first principles molecular dynamics simulations of the solvation of an oxygenated silicon cluster with expli…

多孔硅中通过氯金酸直接还原制备孔内金纳米颗粒实现等离子体增强光致发光

Plasmonic-enhanced photoluminescence in porous silicon with pore-embedded gold nanoparticles fabricated by direct reduction of chloroauric acid

本研究通过在多孔硅光子结构内直接还原氯金酸合成金纳米颗粒，利用等离子体近场增强实现了多孔硅光致发光六倍提升，主要贡献在于解决了金纳米颗粒尺寸和位置控制难题，并展示了其在发光器件和传感器中的应用潜力。

Characterisation of polystyrene coatings after plasma immersion ion implantation and adsorption of protein

A polystyrene film spun onto polished silicon substrates was implanted with either nitrogen or argon ions using plasma immersion ion implantation (PIII) and subsequently investigated by X-ray and neutron reflectometry, UV-VIS and FTIR ellipsometry, as well as by FTIR and Raman spectroscopy. The depth profile of the densified carbon structures resulting from the ion collision cascades in the polystyrene coating are clearly observed by both X-ray and neutron reflectometry. Argon ions produce a higher density modified layer at a shallower depth than nitrogen ions. The thickness measured for these…

Electrical excitation of silicon-vacancy centers in single crystal diamond

Electrically driven emission from negatively charged silicon-vacancy, (SiV)- centres in single crystal diamond is demonstrated. The SiV centres were generated using ion implantation into an intrinsic (i) region of a p-i-n single crystal diamond diode. Both electroluminescence and the photoluminescence signals exhibit the typical emission that is attributed to the (SiV)- centres. Under forward and reversed biased PL measurements, no signal from the neutral (SiV)0 defect could be observed. The realization of electrically driven (SiV)- emission is promising for scalable nanophotonics devices empl…

基于化学-力学核壳模型的硅纳米颗粒缓慢电压弛豫

Slow Voltage Relaxation of Silicon Nanoparticles with a Chemo-Mechanical Core-Shell Model

本文提出化学-力学核壳模型，将硅纳米颗粒视为被固态电解质界面覆盖的核壳结构，用壳层粘弹塑性行为解释硅负极在循环和弛豫期间的电压滞后及对数型电压弛豫，并优于经验Plett模型。

Deep UV laser induced periodic surface structures on silicon formed by self-organization of nanoparticles

We have investigated the formation of laser-induced periodic surface structures (LIPSS or ripples) on silicon upon excitation with p-polarized excimer laser pulses in the deep ultraviolet region (wavelength = 193 nm, pulse duration = 20 ns). Well-pronounced ripples with a period close to the laser wavelength were observed for pulse numbers N = 100 or higher, and the ripple period increased with the angle of incidence. While these results seem to be qualitatively consistent with the standard Sipe-theory, we observed a fundamentally different ripple formation mechanism and ripple morphology. At …