A. Polman's research while affiliated with AMOLF and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (262)
We demonstrate a soft-imprint nanofabrication technique offering nanometer resolution over an area as large as a 150 mm diameter wafer. It makes use of a composite imprint stamp composed of a quaternary siloxane-modified poly-di-methyl-siloxane patterned rubber layer with a relatively high Young's modulus that is laminated on a thin glass support....
Cathodoluminescence (CL) spectroscopy provides a powerful way to characterize optical properties of materials with deep-subwavelength spatial resolution. While CL imaging to obtain optical spectra is a well-developed technology, imaging CL lifetimes with nanoscale resolution has only been explored in a few studies. In this paper we compare three di...
Conventional vertically-stacked, series-connected tandems have shown to reach higher efficiencies than single-junction solar cells. However, the inherent problems of this geometry are the need for current-matching, transparent intermediate (electrode) layers and/or epitaxial growth constraints. In addition, fabrication of (epitaxial) layer stacks i...
Cathodoluminescence (CL) spectroscopy is a technique that can be used to unravel optical and material properties at the nanoscale. This article describes a novel CL detection system. The system sensitivity, the modularity, and the capability to perform angle-resolved CL imaging enable many new research directions. We introduce the technique and giv...
We present a novel soft-nanoimprint procedure to fabricate high-quality sub-wavelength hole arrays in optically thick films of gold on glass substrates. We fabricate 0.5 × 0.5 mm2 structures composed of a square array of 180 nm-diameter holes with a 780 nm pitch. Optical angular transmission measurements on the arrays show clear extraordinary trans...
We determine the angle and polarization dependent emission from 1.75 μm and 2.50 μm long InP nanowires by using cathodoluminescence polarimetry. We excite the vertical wires using a 5 keV electron beam, and find that the 880 nm bandgap emission shows azimuthally polarized rings, with the number of rings depending on the wire height. The data agree...
We present a simple, low-cost, and scalable approach for the fabrication of efficient nanorod-based solar cells. Templates with arrays of self-assembled ZnO nanorods with tunable morphology are synthesized by chemical bath deposition using a low process temperature at 80 °C. The nanorod templates are conformally coated with hydrogenated amorphous s...
Dielectric nanoparticle arrays have been proposed as antireflection coatings and light-trapping schemes for thin-film c-Si solar cells. However, practical aspects about the integration of these nanostructures with solar modules have yet to be investigated. In this paper, we study the effect of ethylene vinyl acetate (EVA) encapsulation on the optic...
We present a method to separate coherent and incoherent contributions to cathodoluminescence from bulk materials by using angle-resolved cathodoluminescence spectroscopy. Using 5 and 30 keV electrons, we measure the cathodoluminescence spectra for Si, GaAs, Al, Ag, Au, and Cu and determine the angular emission distributions for Al, GaAs, and Si. Al...
Numerous optical technologies and quantum optical devices rely on the
controlled coupling of a local emitter to its photonic environment,
which is governed by the local density of optical states (LDOS).
Although precise knowledge of the LDOS is crucial, classical optical
techniques fail to measure it in all of its frequency and spatial
components....
High-performance integrated optics, solar cells, and sensors require nanoscale optical components at the surface of the device, in order to manipulate, redirect and concentrate light. High-index dielectric resonators provide the possibility to do this efficiently with low absorption losses. The resonances supported by dielectric resonators are both...
We experimentally compare the light trapping efficiency of dielectric and metallic backscattering patterns in thin-film a-Si:H solar cells. We compare devices with randomly patterned Ag back contacts that are covered with either flat or patterned aluminum-doped ZnO (AZO) buffer layers and find the nanostructure at the AZO/a-Si:H interface is key to...
A series of (n–i–p) a-Si:H solar cells with light-trapping by front-side plasmonic Ag nanoparticle arrays was compared to a reference without the plasmonic arrays as well as to a benchmark with a conventional textured back-side reflector for light-trapping. The external quantum efficiency of the solar cells was determined experimentally by spectral...
We present a nano-patterned dielectric coating for crystalline Si solar cells that combines excellent anti-reflection and passivation properties. The nano-patterned coating comprises an array of TiO2 nanocylinders placed on top of an ultra-thin Al2O3 layer on a flat Si(100) wafer. The antireflection effect stems from the preferential forward scatte...
Numerous optical technologies and quantum optical devices rely on the controlled coupling of a local emitter to its photonic environment, which is governed by the local density of optical states (LDOS). Although precise knowledge of the LDOS is crucial, classical optical techniques fail to measure it in all of its frequency and spatial components....
Metal nanoparticles are efficient antennas for light. If embedded in a semiconductor material, they can enhance light absorption in the semiconductor, due to the strong plasmonic near-field coupling. We use numerical simulations to calculate the absorption enhancement in the semiconductor using Ag nanoparticles with diameters in the range 5–60 nm f...
Supplementary Figures S1-S6.
Reflection is a natural phenomenon that occurs when light passes the interface between materials with different refractive index. In many applications, such as solar cells or photodetectors, reflection is an unwanted loss process. Many ways to reduce reflection from a substrate have been investigated so far, including dielectric interference coatin...
Plasmonic nanostructures have been recently investigated as a possible way to improve absorption of light in solar cells. The strong interaction of small metal nanostructures with light allows control over the propagation of light at the nanoscale and thus the design of ultrathin solar cells in which light is trapped in the active layer and efficie...
We present a novel method for fabricating polarization-stable oxide-confined single-mode
GaAs based vertical cavity surface emitting lasers (VCSELs) emitting at 850 nm using a
new soft-lithography nano-imprint technique. A monolithic surface grating is etched in the
output mirror of the laser cavity using a directly imprinted silica-based sol–gel i...
We propose a design for a plasmonic copper metamaterial with a negative index of refraction at visible/near-infrared wavelengths. Using numerical simulations, we demonstrate negative refraction by a copper metamaterial prism and perform a parameter extraction technique to verify the sign of the effective, electric permittivity and magnetic permeabi...
We demonstrate the first optical metamaterial with a three-dimensional negative index in the blue/UV spectral range. Using focused ion beam milling and evaporation we fabricate Ag/Si3N4 multilayer structures composed of coupled metal/insulator/metal (MIM) plasmonic waveguides. Article not available.
We have fabricated microphotonic parabolic light directors using two-photon lithography, thin-film processing, and aperture formation by focused ion beam lithography. Optical transmission measurements through upright parabolic directors 22 μm high and 10 μm in diameter exhibit strong beam directivity with a beam divergence of 5.6°, in reasonable ag...
Metal nanoparticles are efficient resonant plasmonic scatterers for light, and, if placed on top of a high-index substrate, can efficiently couple light into the substrate. This coupling, however, strongly depends on particle shape and surrounding environment. We study the effect of particle shape and substrate refractive index on the plasmonic res...
We investigate the influence of nanoparticle height on light trapping in thin-film solar cells covered with metal nanoparticles. We show that in taller nanoparticles the scattering cross-section is enhanced by resonant excitation of plasmonic standing waves. Tall nanoparticles have higher coupling efficiency when placed on the illuminated surface o...
We provide a new physical interpretation of scattering from plasmonic nanoparticles on high-index substrates. We demonstrate the excitation of different types of resonant modes on disk-shaped, Ag nanoparticles. At short wavelengths, the resonances are localised at the top of the particle, while at longer wavelengths they are localised at the Ag/sub...
Silver nanoparticle arrays placed on top of a high-refractive index substrate enhance the coupling of light into the substrate over a broad spectral range. We perform a systematic numerical and experimental study of the light incoupling by arrays of Ag nanoparticle arrays in order to achieve the best impedance matching between light propagating in...
Bombardment damage produced by Si+ ions in AlxGa1−xAs/GaAs layer structures has been studied using transmission electron microscopy and ion channeling and backscattering spectrometry. The damage resistance of A1xGa1−xAs alloy layers increases with Al concentration. In particular, by comparison of complementary Si+ ion doses yielding similar nuclear...
Solid phase epitaxy and ion-beam-induced epitaxial crystallization of Er-doped amorphous Si are used to incorporate high concentrations of Er in crystal Si. During solid phase epitaxy, substantial segregation and trapping of Er is observed, with maximum Er concentrations trapped in single crystal Si of up to 2 × 1020 /cm3. Ion-beam-induced regrowth...
Synthesis and size-dependent photoluminescence has been performed for Ge nanocrystals in SiO2 matrices with average diameters between 2 nm and 9 nm, formed by room temperature ion implantation into SiO2 followed by precipitation during vacuum thermal anneals. Nanocrystal size distributions obtained from electron microscopy data were used in conjunc...
Pulsed laser irradiation is used to induce epitaxial explosive crystallization of amorphous silicon layers buried in a (100) oriented crystalline matrix. This process is mediated by a self-propagating liquid layer. Time-resolved determination of the crystallization speed combined with numerical calculation of the interface temperature shows that fr...
Solid phase epitaxy and ion-beam-induced epitaxial crystallization of Er-doped amorphous Si are used to incorporate high concentrations of Er in crystal Si. During solid phase epitaxy, substantial segregation and trapping of Er is observed, with maximum Er concentrations trapped in single crystal Si of up to 2 x 1020 /cm3. Ion-beam-induced regrowth...
The effect of ion implantation damage on energy transfer processes in Er-doped silica films prepared by MeV ion implantation is studied, using measurements of the luminescence decay of Er3+(4ƒ11) at 1.535 μm. Silica films implanted with Er and annealed at 900°C show a luminescence lifetime of 14.1 ms. Subsequent irradiation with MeV C, Si, or Ge io...
It is demonstrated room-temperature electroluminescence at 1.54 μm in erbiumimplanted oxygen doped silicon (27 at. 0), due to intra-4f transitions of the Er3+. The luminescence is electrically stimulated by biasing metal-(Si:O,Er)-p+ silicon diodes. The 30 nm thick Si:O,Er films are amorphous layers deposited onto silicon substrates by chemical vap...
Temperature quenching of the 1.54 μm photoluminescence intensity and lifetime of Er in crystal Si was investigated between 12 K and 150 K. A p-type Czochralski-grown Si (100) wafer was doped with Er to a peak concentration of 5×1018 cm−3 using 1.5 MeV ion implantation. The Er doped layer was co-implanted with N to a peak concentration of 6×1019 N c...
Plastic deformation of several covalently-bound materials has been studied during ion irradiation. In all of these materials, namely crystalline and amorphous silicon, crystalline and amorphous Si 0.9 Ge 0.1 , and amorphous SiO 2 , the damage created by the ion beam causes density changes in the irradiated region which eventually saturate with ion...
Synthesis of Ge nanocrystals in SiO2 is carried out by precipitation from a supersaturated solid solution of Ge in SiO2 made by Ge ion implantation. The SiO2films containing Ge nanocrystals show intense visible photoluminescence at room temperature that is very similar in spectral features to that of SiO2 containing Ge nanocrystals synthesized by o...
Amorphous SiO2 films, 10 μm thick, were grown on Si(100) substrates and subsequently implanted with 5.0×1015 Er ions/cm2 at an energy of 3.5 MeV. When optically pumped at λ = 488 nm, the implanted films show a sharply peaked photoluminescence spectrum centred around λ. = 1.54 μm, corresponding to an intra-4f transition of Er3+. Thermal treatment at...
A novel method of pulsed laser processing of ion-implanted silicon is presented, in which samples are irradiated in water ambient. The water layer in contact with the silicon during irradiationh as a considerable influence on melting and solidificationd ynamics. Still, perfect epitaxy of a thin amorphous layer can be obtained using this method.
For...
Nitridation and oxidation of titanium is achieved by pulsed laser irradiation of Ti immersed in liquid ammonia or water. Rutherford Backscattering Spectrometry shows that large amounts of nitrogen and oxygen can be incorporated in the metal surface to a depth of several 1000 Å. X-ray diffraction shows evidence of compound formation. Scanning Electr...
420 nm thick amorphous Si layers buried in a Si (100) or Si (111) matrix, produced by 350 keV Si-implantation, were irradiated using a pulsed ruby laser. Time-resolved reflectivity measurements show that melting can be initiated buried in the samples at the crystalline-amorphous interface. Melting is immediately followed by explosive crystallizatio...
Advanced light management in thin-film solar cells is becoming increasingly important to reduce semiconductor layer thicknesses (and thus costs) while still absorbing the full solar spectrum in the cell. Here, we discuss how the excitation of surface plasmon resonances in metal nanoparticles can serve to enhance the trapping of light in thin-film s...
We show experimentally that there is asymmetry in photocurrent enhancement by Ag nanoparticle arrays located on the front or on the rear of solar cells. The scattering cross-section calculated for front- and rear-located nanoparticles can differ by up to a factor of 3.7, but the coupling efficiency remains the same. We attribute this to differences...
Integrated circuit components have nowadays reached dimensions much smaller than the dimensions of typical micro-optical components. This " size mismatch " is regarded as a practical concern for a variety of integrated optics applications. The application of surface plasmon polaritons (SPPs) generated at metal/dielectric interfaces provides light c...
The spontaneous emission rate of erbium ions is enhanced by coupling to localized plasmonic resonances in subwavelength annular apertures in a Au film. The Er3+ ions, embedded in SiO2, are selectively located inside the apertures. The annular apertures act as nanocavities, enhancing the local density of optical states at the Er emission wavelength...
After decades of process scaling driven by Moore's law, the silicon microelectronics world is now defined by length scales that are many times smaller than the dimensions of typical micro-optical components. This size mismatch poses an important challenge for those working to integrate photonics with complementary metal oxide semiconductor (CMOS) e...
We experimentally and theoretically determine the plasmon dispersion in coaxial waveguides. We demonstrate strong optical confinement at energies below the surface plasmon resonance. Furthermore, we find that the reflection coefficients of the coax end facets can be strongly tuned by changing the coax dispersion and surrounding dielectric, which pr...
We experimentally and theoretically determine the plasmon dispersion in coaxial waveguides. We demonstrate strong optical confinement at energies below the surface plasmon resonance. Furthermore, we find that the reflection coefficients of the coax end facets can be strongly tuned by changing the coax dispersion and surrounding dielectric, which pr...
We present criteria for optimizing the light-trapping efficiency of periodic arrays of metal nanoparticles for Si solar cell applications. The scattering cross section of the nanoparticles and the diffraction efficiency of the grating should be maximized in the long wavelength range. The grating pitch should be chosen to allow higher order diffract...
Scattering processes in an optical microcavity are investigated for the case of silicon nanocrystals embedded in an ultra-high-Q toroid microcavity. Using a novel measurement technique based on the observable mode splitting, we demonstrate that light scattering is highly preferential: more than 99.8% of the photon flux is scattered into the origina...
Effective light management is imperative in maintaining high efficiencies as photovoltaic devices become thinner. We demonstrate a simple and effective method of enhancing light trapping in solar cells with thin absorber layers by tuning localized surface plasmons in arrays of Ag nanoparticles. By redshifting the surface plasmon resonances by up to...
Surface plasmon polariton Fabry–Pe´rot resonators were made in single-crystalline gold by focused ion beam milling of two parallel 100 nm deep grooves. The plasmonic cavity modes were spatially and spectrally resolved using cathodoluminescence spectroscopy. Mode numbers up to n=10 were observed. The cavity quality factor Q depends strongly on groov...
The surface plasmon polariton (SPP) field intensity in the vicinity of gratings patterned in an otherwise planar gold surface is spatially resolved using cathodoluminescence (CL). A detailed theoretical analysis is presented that successfully explains the measured CL signal based upon interference of transition radiation directly generated by elect...
We report highly efficient generation of propagating plasmons by electron beams in planar films, planar dielectric cavities, metallic wires, and nanoparticle waveguides. Electron-induced plasmon excitation is investigated in (1) gold thin films, both free-standing or supported on a silica substrate, (2) gold-silica-gold planar cavities, (3) gold na...
The scattering from metal nanoparticles near their localized plasmon resonance is a promising way of increasing the light absorption in thin-film solar cells. Enhancements in photocurrent have been observed for a wide range of semiconductors and solar cell configurations. We review experimental and theoretical progress that has been made in recent...
Ag nanoparticle arrays, located on the front or rear surface of a Si solar cell, can provide effective light-trapping via the excitation of localised surface plasmons. We identify key parameters in engineering random Ag nanoparticle arrays for optimum plasmonic light-trapping. We demonstrate that there is an asymmetry in scattering behaviour betwee...
We develop fundamental design principles for increasing the efficiency of solar cells using light trapping by scattering from metal nanoparticles. We show that cylindrical and hemispherical particles lead to much higher path length enhancements than spherical particles, due to enhanced near-field coupling, and that the path length enhancement for a...
We review recent progress and report new results on the use of particle plasmons to enhance the efficiency of solar cells. We describe the basic mechanisms at work, and provide an outlook on future prospects.
![[(a) and (b)] AFM images of gold films evaporated at room temperature...](profile/Martin-Kuttge/publication/30769528/figure/fig3/AS:289044455018505@1445924976666/a-and-b-AFM-images-of-gold-films-evaporated-at-room-temperature-a-and-onto-a_Q320.jpg)
We use cathodoluminescence imaging spectroscopy to excite surface plasmon polaritons and measure their decay length on single crystal and polycrystalline gold surfaces. The surface plasmon polaritons are excited on the gold surface by a nanoscale focused electron beam and are coupled into free space radiation by gratings fabricated into the surface...
![(a) FDTD calculation snapshot [at t = 10 in Fig. 1(b)] of the x...](profile/Alfons-Van-Blaaderen/publication/224455217/figure/fig6/AS:289403126730794@1446010490918/a-FDTD-calculation-snapshot-at-t-10-in-Fig-1b-of-the-x-component-of_Q320.jpg)
Core-shell colloids composed of a dielectric core surrounded by a metal shell show geometric cavity resonances with optical properties that are distinctly different than those of the collective plasmon modes of the metal shell. We use finite-difference time domain calculations on silica colloids with a core diameter of 456 nm , surrounded by a 38 n...
We use focused-ion-beam milling of a single-crystal Au surface to fabricate a 590- nm -long linear ridge that acts as a surface plasmon nanoresonator. Cathodoluminescence imaging spectroscopy is then used to excite and image surface plasmons on the ridge. Principal component analysis reveals distinct plasmonic modes, which proves confinement of sur...
The surface plasmon modes of spherical and oblate spheroidal core−shell colloids composed of a 312 nm diameter silica core and a 20 nm thick Au shell are investigated. Large arrays of uniaxially aligned core−shell colloids with size aspect ratios ranging from 1.0 to 1.7 are fabricated using a novel ion irradiation technique. Angle- and polarization...
Si/SiOx heterostructures show a photovoltaic effect when the samples are annealed to form Si quantum dots. Subsequently applying dielectric breakdown increases the short-circuit current by up to an order of magnitude.
In this work, we realize light emitting functional multilayer (Al2O3 / Si-nanocrystals (Si-NC)) stacks at low temperatures (300-325 °C) by a combination of ALD and CVD techniques. The multilayer structure was obtained by a sequential deposition of a 20 nm-thick ALD Al2O3 film, followed by LPCVD of a Si-NC layer, without vacuum break. A high nanocry...
We present a theoretical study of the radiative and nonradiative decay rates of an optical emitter in close proximity to a prolate-shaped metal nanoparticle. We use the model developed by Gersten and Nitzan, that we correct for radiative reaction and dynamic depolarization and extend for prolate particle shapes. We show that prolate-shaped metal na...
![Fig. 1. High resolution SEM image of the Si inverse opal. [111] plane...](profile/Willem-Vos-2/publication/228933701/figure/fig1/AS:393844186206212@1470911179517/High-resolution-SEM-image-of-the-Si-inverse-opal-111-plane-of-a-silicon-inverse-opal_Q320.jpg)
We present ultrafast optical switching experiments on 3D photonic band gap crystals. Switching the Si inverse opal is achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of second order Bragg diffraction where the photonic band gap is predicted. We observe a large frequency shift of up...
It is demonstrated that the photoluminescence intensity of optically active erbium ions positioned in close proximity of anisotropic Ag nanoparticles is significantly enhanced if the nanoparticles support plasmon modes that are resonant with the erbium emission. In addition, the photoluminescence intensity enhancement is found to be polarized corre...
We present an investigation of the Ag-nanocrystal depth profile as well as the corresponding refractive index depth profile of borosilicate glass that was first doped with Ag by Na+ ↔ Ag+ ion exchange and subsequently irradiated with 1 MeV Xe ions. By combining RBS, XPS, XE-AES, and transmission and reflection spectroscopy, we show unambiguously th...
We develop a phenomenological model for size-dependent anisotropic plastic deformation of colloidal nanoparticles under ion irradiation. We show that, at the nanoscale, nonhydrostatic capillary stresses drive radiation-induced Newtonian viscous flow, counteracting the stress state that initiates the anisotropic viscous strains in the high-temperatu...
An erbium doped micro-laser is demonstrated utilizing $\mathrm{SiO_{2}}$ microdisk resonators on a silicon chip. Passive microdisk resonators exhibit whispering gallery type (WGM) modes with intrinsic optical quality factors of up to $6\times{10^{7}}$ and were doped with trivalent erbium ions (peak concentration $\mathrm{\sim3.8\times{10^{20}cm^{-3...
An erbium-doped microlaser is demonstrated utilizing SiO2 microdisk resonators on a silicon chip. Passive microdisk resonators exhibit whispering-gallery-type modes (WGM's) with intrinsic optical quality factors of up to 6x10(7) and were doped with trivalent erbium ions (peak concentration similar to 3.8x10(20) cm(-3)) using MeV ion implantation. C...
Cathodoluminescence imaging spectroscopy is used to determine the propagation distance of surface plasmon polaritons near the surface plasmon resonance on both silver and gold films. Surface plasmon polaritons are generated by a focused (diameter of 5 nm ) electron beam spot in the metal and coupled out through a grating. By gradually varying the d...
Erbium-doped SiO2 toroidal microcavity lasers are fabricated on a Si substrate using a combination of optical lithography, etching, Er ion implantation, and CO2 laser reflow. Erbium is either preimplanted in the SiO2 base material or postimplanted into a fully fabricated microtoroid. Three-dimensional infrared confocal photoluminescence spectroscop...
The photoluminescence decay characteristics of silicon nanocrystals in dense ensembles fabricated by ion implantation into silicon dioxide are observed to vary in proportion to the calculated local density of optical states. A comparison of the experimental 1∕e photoluminescence decay rates to the expected spontaneous emission rate modification yie...
We demonstrate a new technique to spatially map the propagation and damping of infrared surface plasmon polaritons (SPPs) on metal films using optically active erbium ions as a probe of the SPP field. The bound SPP mode propagating along the Ag/glass interface of a 96 nm thick Ag film on glass is excited by illuminating a subwavelength hole array i...
The excitation of surface plasmons (SPs) by optically excited silicon quantum dots (QDs) located near a Ag interface is studied both experimentally and theoretically for different QD-interface separations. The Si QDs are formed in the near-surface region of an SiO2 substrate by Si ion implantation and thermal annealing. Photoluminescence decay-rate...
We have studied the deformation of metallo-dielectric core–shell colloids under 4 MeV Xe, 6 and 16 MeV Au, 30 MeV Si and 30 MeV Cu ion irradiation. Colloids of silica surrounded by a gold shell, with a typical diameter of 400 nm, show anisotropic plastic deformation under MeV ion irradiation, with the metal flowing conform the anisotropically defor...
Spherical silica optical microresonators were doped with erbium ions by ion implantation at energies of 925 keV and 2.05 MeV using a rotating stage. After thermal annealing at 800 °C, light was coupled into the microsphere using a tapered optical fiber. An optical quality factor as high as 1.9 × 107 was observed at λ = 1450 nm, corresponding to a m...
We present a numerical analysis of surface plasmon waveguides exhibiting both long-range propagation and spatial confinement of light with lateral dimensions of less than 10% of the free-space wavelength. Attention is given to characterizing the dispersion relations, wavelength-dependent propagation, and energy density decay in two-dimensional Ag/S...
We present time-resolved reflectivity spectra of optically, homogeneously switched photonic crystals. We observe large, ultrafast shifts of stopbands of GaAs/AlAs multilayer structures as well as in the photonic bandgap range of 3D Si inverse opals.
A numerical analysis of surface plasmon dispersion, propagation, and localization on smooth lossy films is presented. Particular attention is given to determining wavelength-dependent behavior of thin Ag slab waveguides embedded in a symmetric SiO2 environment. Rather than considering Ag as a damped free electron gas, the metal is defined by the ex...
Scattering induced by nano-particles in a microcavity is investigated for the case of silicon nanocrystal doped microtoroids and a significant enhancement of scattering into the originally doubly-degenerate cavity eigenmodes is found, exceeding >99.42%.
Scattering processes in an optical microcavity are investigated for the case of silicon nanocrystals embedded in an ultra-high Q toroid microcavity. Using a novel measurement technique based on the observable mode-splitting, we demonstrate that light scattering is highly preferential: more than 99.8% of the scattered photon flux is scattered into t...
Scattering induced by silicon nano-particles in a microcavity is investigated for the case of
silicon nanocrystal doped microtoroids. A significant enhancement of preferential-scattering
into the originally doubly-degenerate cavity eigenmodes is found, exceeding >99.42%.
We present measurements of the optical absorption cross section of the → transition at 1.5 μm of Er3+ ions embedded in SiO2 and Si-rich oxide, using cavity ringdown spectroscopy on thin films. The peak absorption cross section for Er3+ embedded in Si-rich oxide (10 at. % excess Si) was found to be (8±2)×10−21 cm2 at 1536 nm, similar to typical valu...
Linear arrays of very small Ag nanoparticles (diameter ~10 nm, spacing 0–4 nm) were fabricated in sodalime glass using an ion irradiation technique. Optical extinction spectroscopy of the arrays reveals a large polarization-dependent splitting of the collective plasmon extinction band. Depending on the preparation condition, a redshift of the longi...
Optically excited erbium ions incorporated near the surface of a silica glass decay by spontaneous emission and—at high Er concentration—via Förster energy transfer to quenching sites. By externally modifying the photonic microstructure we vary the local optical density of states (LDOS) in samples with different degrees of Förster transfer. Changes...
Er3+ ions located 100 nm beneath the surface of silica glass show an enhanced photoluminescence decay rate when the glass is covered with Ag. Correcting for concentration quenching effects, the decay rate is enhanced by 70%, compared to the case without Ag. The data are in agreement with a model that takes into account variations in local density o...
A model describing the origin of ion beam-induced anisotropic plastic deformation is derived and discussed. It is based on a viscoelastic thermal spike model for viscous flow in single ion tracks earlier derived. Deviatoric (shear) stresses, brought about by the rapid thermal expansion of the thermal spike, relax at ion track temperatures beyond a...
An ultra-low threshold erbium-doped silica microcavity laser operating at 1.5 μm is presented. The toroidally-shaped silica glass microcavity is made on a Si substrate using standard CMOS fabrication technology in combination with a laser reflow process. Light is coupled into the toroidal laser cavity using a tapered optical fiber that is evanescen...
Optically active and electrically excitable erbium complexes on silicon are made by wet-chemical synthesis. The single-crystalline Er–Si–O compound is formed by coating a Si(100) substrate with an ErCl3∕ethanol solution, followed by rapid thermal oxidation and annealing. Room-temperature Er-related 1.53 μm photoluminescence is observed with a peak...
An azobenzene-functionalized photoaddressable polymer films that has been engineered to maximize birefringence were analyzed. The extinction spectrum of a thin polymer film calculated from transmission and reflectance data obtained via spectroscopic ellipsometry was shown. A writing intensity of 1.5 W cm -2 produced maximal birefringence due to enh...
We present two-dimensional arrays of silver nanoparticles embedded in amorphous silicon, fabricated by a sequential Si / Ag / Si electron-beam evaporation process. The particle arrays exhibit surface plasmon resonance spectra in the near-infrared (0.9 eV ) , with tails extending below 0.5 eV . The data are compared with calculations that take into...
The dynamic competition between structural transformation, Newtonian viscous flow, and anisotropic strain generation during ion irradiation of SiO2, leads to strongly depth-dependent evolution of the mechanical stress, ranging between compressive and tensile. From independent in situ stress measurements during irradiation, generic expressions are d...
Silicon nanocrystals embedded in SiO2 were isolated with a selective etching procedure, and the isolated nanocrystals' excitonic emission energy was studied during controlled oxidation. Nanocrystals having initial diameters, d(0), of similar to 2.9-3.4 nm showed a photoluminescence (PL) blueshift upon oxidatively induced size reduction, as expected...
Amorphous silicon micropillars show anisotropic plastic shape changes upon irradiation with 30 MeV Cu ions. The transverse plastic strain rate is (2.5+/-0.2)×10-17 cm2/ion at 77 K, which is about one order of magnitude less than that of silica glass. In contrast, crystalline silicon pillars, irradiated under the same conditions, do not exhibit anis...
Optically active erbium ions in the silica and silicon sections of a Si-infiltrated silica colloidal photonic crystal can be separately addressed. A face-centered cubic colloidal crystal composed of 860 nm silica colloids was made by self-assembly under controlled drying conditions. It was then infiltrated with Si using chemical vapor deposition at...
We present an erbium-doped microlaser on silicon operating at a wavelength of 1.5 mum that operates at a launched pump threshold as low as 4.5 muW. The 40 mum diameter toroidal microresonator is made using a combination of erbium ion implantation, photolithography, wet and dry etching, and laser annealing, using a thermally grown SiO2 film on a Si...
Citations
... In order to experimentally demonstrate the proposed nanophotonic light trapping structure, largescale nanopatterns are fabricated on solar cells by Substrate Conformal Imprint Lithography (SCIL) 38,39 . ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272713256271875-1442031315085_Q64/Marc-Verschuuren.jpg)
... Electron microscopes are an indispensable analytic tool, bringing analytic imaging down to an atomic resolution. The rise of the laser-triggered electron (e − -)microscope [1][2][3][4] added ultrafast dynamics capabilities to the sub-nm spatial sensitivity [5][6][7][8] and opened a viable path towards quantum entanglement between free electrons and photons [9][10][11]. In such instruments, the temporal features of the electron pulses determine the accessible physics. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/651666240061440-1532380747802_Q64/Sophie-Meuret-2.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/1025884282691587-1621601281877_Q64/Magdalena-Sola-Garcia.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/1154814444613632-1652340627110_Q64/Toon-Coenen.jpg)
... The numerical finite-element-method (FEM) simulations are performed to investigate the field distributions of both the TE and TM modes, which show that the optical modes are further away from the scattering-inducing cavity boundary with a shallower wedge angle [ Fig. 1(c)], leading to a higher Q factor. 12 Empirically, besides controlling the etch time, the wedge angle can also be altered by adjusting the concentration of the buffered HF solution and by adjusting the photoresist adhesion using commercially available adhesion promoters. 18 In the silicon etching process, different from the isotropic dry etch to undercut the microdisk using XeF 2 , 20 the wet etch using TMAH is anisotropic, which results in a silicon pillar with the polygonal shape [see the top-view microscopic image of the disk in Fig. 3(a)]. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/273658094551064-1442256582609_Q64/Tobias-Kippenberg.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/405770786099202-1473754702575_Q64/J-Kalkman.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/700776766791686-1544089609776_Q64/Kerry-Vahala.jpg)
... CL measurements were performed in an SEM instrument (FEI Quanta FEG 650, Thermo Fisher Scientific Inc., MA, USA) equipped with a Schottky field emission electron source and operated at an electron beam current of 570 pA. CL emission was collected by a half-parabolic mirror covering a solid angle of 1.46 π sr above the sample plane and directed into an optical detection system for spectrally resolved CL analysis (SPARC Spectral, DELMIC BV, The Netherlands) 76 . The acquisition time for each spectrum was 350 ms, and the resolution of the spectrometer was on the order of 10 meV (as determined from the sharp emission lines of an argon calibration lamp). ...
... The step-by-step fabrication process is shown in Figure 8. The work conducted in [48] presents the fabrication of a sensor model closely related to the proposed model in this work by using soft nano-imprint lithography. The process involves generating a PDMS stamp through the deposition of silicon on a chromium slab and later using sol-gel resist to form a solid silica model. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272766259691525-1442043952114_Q64/Michiel-De-Dood.jpg)
... Polarization resolved CL, for its part, has been implemented within scanning electron microscopes (SEMs) and transmission electron microscopes (TEMs) for the study of nanowires, 32,33 plasmons, 34,35 and the effect of polarized electrons. 36 However, direct strain measurement from the DOP of CL has not been reported to our knowledge. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/278500788457472-1443411170483_Q64/Benjamin-Brenny-2.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/278595076411395-1443433650157_Q64/Dick-Van-Dam-2.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/533085885931520-1504108987836_Q64/Jaime-Rivas.jpg)
... Radially stacked p-n or p-i-n junction designs have attracted much attention, where the charge collection path is in the radial direction and the light path is in the vertical direction along the core. [82][83][84][85][86] To form such core-shell RJ structure, different designed nano-architectures have been investigated/used as the core, such as nanowire, [86][87][88][89] nanorod, [90][91][92][93] nanopyramid, [94][95][96] nano-cone, [97][98][99] and so on. Among these nano-architectures, the nanowire is the most popular choice to fabricate such radially stacked core-shell structure, for example, using the Si nanowire (SiNW) as a core to host amorphous Si thin film to form c-Si/a-Si core-shell, [100][101][102] or III-V thin film as a shell to form such as Si/InP core-shell. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/278903110291458-1443507091195_Q64/Yinghuan-Kuang.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/11431281233281818-1711986955000_Q64/Claire-Van-Lare.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/379115841572865-1467399668480_Q64/Pim-Veldhuizen.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/273752873238541-1442279180001_Q64/Rei-Schropp.jpg)
... The solar array, which is made up of interconnected solar panels or modules, is designed to meet the power requirements of the load [3]. The encapsulation process is crucial in providing mechanical rigidity and environmental protection to the solar cell matrix [4]. However, it is important to note that once encapsulation is complete, the solar cells and connections become a monolithic structure, rendering modifications to the cells or connections impossible. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/272785276665872-1442048486980_Q64/Aw-Weeber.jpg)
... A maximum EQE for the first device had a value close to 5.5×10 −6 under QTH lamp 1523nm excitation. This value is only a few times larger than the measurements performed on Er 3+ doped Si PERL cells (for IPV applications) using a similar excitation source, as published by Dood et al. [70] based on measurements by Keevers et al. [15,16] where an EQE value of close to 2.1×10 −6 was measured at 1535nm excitation. ...
... Ion irradiation of the substrate causes density changes and broken bonds. Plastic flow may release the resulting stress, such as by cooperative motion of defects [44,45]. Therefore, the irradiated substrate may be described as a fluid with a given viscosity [46]. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/459048706416640-1486457148323_Q64/Cynthia-Volkert.jpg)
