Riconosciamo JL Paul Webster per il rendering 3D dei dati ottici con Amira. Phil Muñoz e Benjamin Franta fornito un feedback sul manoscritto tutto il suo sviluppo. La ricerca descritta in questo documento è stata sostenuta dall&#39;Ufficio Air Force della ricerca scientifica in base a concessioni FA9550-09-1-0546 e FA9550-10-1-0402.

1. Preparazione metallo-ioni Doped film polimerico <ol><li> Misurare 8 ml di acqua in un becher. </li><li> Aggiungere 206 mg di PVP all&#39;acqua. Miscelare con agitatore magnetico o vortex finché la soluzione è limpida. </li><li> Aggiungere 210 mg di soluzione di AgNO 3. Miscelare con agitatore magnetico o vortex fino a soluzione è chiara. </li><li> Cappotto vetrino con la soluzione attraverso la fusione goccia. </li><li> Posto vetrino in una serie forno a 100 ° C. Cuocere campione per 30 min. </li><li> Togliere il campione dal forno e lasciate raffreddare per 30 minuti. </li></ol> 2. Fabbricazione di strutture d&#39;argento disconnesse <ol><li> Allineare la configurazione illustrata nella figura 1 il tavolo ottico con antivibranti. </li><li> Regolare compressore per ottenere 50-FSEC impulsi dopo obiettivo microscopio. </li><li> Regolare filtri a densità neutra per ottenere 3-NJ impulsi dopo l&#39;obiettivo. </li><li> Assicurarsi dimensione dello spot laser è più grande apertura posteriore dell&#39;obiettivo microscopio. </li><li>Impostare acustoottico modulatore per produrre 10-psec finestre di esposizione durante la quale viene irradiato il campione. </li><li> Fascio laser blocco prima che raggiunga il campione microscopio e posto su tre assi stadio di traslazione. Il percorso del fascio di impulsi laser a femtosecondi le deve passare attraverso l&#39;obiettivo microscopio imaging e nel campione. </li><li> Accendere la sorgente di illuminazione microscopio per osservare il campione in-situ con camera CCD. </li><li> Tradurre asse z di fase per trovare all&#39;interfaccia tra il substrato di vetro e il film polimerico. Poi, riorientare microscopio alla profondità desiderata all&#39;interno polimero per patterning fondo-più strato. Z-traduzione durante patterning deve essere nella direzione opposta al vetro polimero interfaccia per evitare dispersione con strutture fabbricate. </li><li> Sblocca raggio laser e set motion-controller di software per tradurre campione in x -, y - z - le direzioni con velocità di 100 micron / sec. Irradiare voxel singolo per 10 msec unnd voxel vicini separati da almeno diversi micrometri per una chiara in-situ di imaging. Impostazione acustoottico frequenza di ripetizione modulatore a 25 Hz produrrà 4 micron spaziatura. Aree esposte al laser conterrà strutture d&#39;argento. </li></ol>

<ol>
	<li>von Freymann, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-Dimensional+Nanostructures+for+Photonics.">Three-Dimensional Nanostructures for Photonics.</a> Advanced Functional Materials. 20, 1038-1052 (2010).</li><li>LaFratta, C. N., Fourkas, J. T., Baldacchini, T., Farrer, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiphoton+Fabrication.">Multiphoton Fabrication.</a> Angewandte Chemie International Edition. 46, 6238-6258 (2007).</li><li>Gattass, R. R., Mazur, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Femtosecond+laser+micromachining+in+transparent+materials.">Femtosecond laser micromachining in transparent materials.</a> Nat. 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F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+spatial+resolution+of+two-photon+microfabrication+by+using+photoinitiator+with+high+initiating+efficiency.">Improving spatial resolution of two-photon microfabrication by using photoinitiator with high initiating efficiency.</a> Appl. Phys. Lett. 90, 131106 (2007).</li><li>Tan, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduction+in+feature+size+of+two-photon+polymerization+using+SCR500.">Reduction in feature size of two-photon polymerization using SCR500.</a> Appl. Phys. Lett. 90, 071106 (2007).</li><li>Vora, K., Kang, S., Shukla, S., Mazur, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+disconnected+three-dimensional+silver+nanostructures+in+a+polymer+matrix.">Fabrication of disconnected three-dimensional silver nanostructures in a polymer matrix.</a> Appl. Phys. Lett. 100, 063120 (2012).</li><li>G&#252;ney, D. &. #. 2. 1. 4. ;., Koschny, T., Soukoulis, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intra-connected+three-dimensionally+isotropic+bulk+negative+index+photonic+metamaterial.">Intra-connected three-dimensionally isotropic bulk negative index photonic metamaterial.</a> Opt. Express. 18, 12348-12353 (2010).</li><li>Grigorenko, A. N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanofabricated+media+with+negative+permeability+at+visible+frequencies.">Nanofabricated media with negative permeability at visible frequencies.</a> Nat. Photon. 438, 335-338 (2005).</li><li>Grigorenko, A. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Negative+refractive+index+in+artificial+metamaterials.">Negative refractive index in artificial metamaterials.</a> Opt. Lett. 31, 2483-2485 (2006).</li><li>Shalaev, V. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Negative+index+of+refraction+in+optical+metamaterials.">Negative index of refraction in optical metamaterials.</a> Opt. 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Lett. 88, 081107 (2006).</li><li>Ishikawa, A., Tanaka, T., Kawata, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvement+in+the+reduction+of+silver+ions+in+aqueous+solution+using+two-photon+sensitive+dye.">Improvement in the reduction of silver ions in aqueous solution using two-photon sensitive dye.</a> Appl. Phys. Lett. 89, 113102 (2006).</li><li>Cao, Y. -. Y., Takeyasu, N., Tanaka, T., Duan, X. -. M., Kawata, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+Metallic+Nanostructure+Fabrication+by+Surfactant-Assisted+Multiphoton-Induced+Reduction.">3D Metallic Nanostructure Fabrication by Surfactant-Assisted Multiphoton-Induced Reduction.</a> Small. 5, 1144-1148 (2009).</li></ol>

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La chiave per il processo è ottenere una matrice dielettrico drogato che consente fabbricazione ad alta risoluzione, ma non degrada subito dopo la preparazione. Una semplice miscela di PVP, AgNO 3 e H 2 O permette la creazione di alta risoluzione nanostrutture argento che sono incorporati all&#39;interno di una matrice di supporto. Variando il PVP di AgNO3 rapporto cambierà l&#39;energia del laser necessaria per la fabbricazione, e le proprietà potenzialmente altre funzionalità come ...

a method to fabricate disconnected silver nanostructures in 3d

Il toolkit nanofabbricazione standard include tecniche volte principalmente a creare modelli 2D in mezzi dielettrici. Creazione di modelli di metallo su una scala inferiore al micron richiede una combinazione di strumenti di nanofabbricazione e diverse fasi di lavorazione dei materiali. Ad esempio, i passaggi per creare strutture metalliche planari usando fotolitografia ultravioletta e litografia a fascio elettronico può includere l&#39;esposizione del campione, lo sviluppo del campione, deposizione del metallo, e decollo metallo. Per creare strutture metalliche 3D, la sequenza viene ripetuta più volte. La complessità e la difficoltà di stoccaggio e allineare più livelli limita implementazioni pratiche di strutturazione metallo 3D utilizzando gli strumenti standard di nanofabbricazione. -Laser a femtosecondi diretta scrittura è emersa come una preminente tecnica di nanofabbricazione 3D. 1,2 laser a femtosecondi sono spesso utilizzati per creare modelli 3D in polimeri e occhiali. 3-7 Tuttavia, metallo 3D diretto scrivendo rimane una sfida. Qui,descrivono un metodo per fabbricare nanostrutture argento incorporati all&#39;interno di una matrice polimerica utilizzando un laser a femtosecondi centrato a 800 nm. Il metodo consente la realizzazione di modelli non realizzabili con altre tecniche, come array 3D di voxel argento sconnessi. 8 pattern metallici disconnesse 3D sono utili per metamateriali pile unitarie quando non sono in contatto tra loro, 9 come metallo dot accoppiata 10, 11 o accoppiato tondino metallico 12,13 risonatori. Le possibili applicazioni includono metamateriali indice negativo, mantelli dell&#39;invisibilità, e lenti perfette. In femtosecondi-laser direct-scrittura, la lunghezza d&#39;onda del laser viene scelto in modo che non siano linearmente fotoni assorbiti nel supporto di destinazione. Quando la durata dell&#39;impulso laser è compresso alla scala dei tempi femtosecondi e la radiazione è ben focalizzato all&#39;interno del bersaglio, l&#39;intensità estremamente alta induce assorbimento non lineare. Più fotoni vengono assorbiti simultanealy causare transizioni elettroniche che portano alla modificazione materiale all&#39;interno della regione concentrato. Usando questo approccio, si può formare strutture nella massa di un materiale piuttosto che sulla sua superficie. La maggior parte dei lavori di scrittura in metallo 3D diretto è concentrata sulla creazione di auto-supportati strutture metalliche. 14-16 Il metodo qui descritto produce sub-micrometriche strutture d&#39;argento che non hanno bisogno di essere auto-sostenuta, perché sono inseriti all&#39;interno di una matrice. Un drogato matrice polimerica è preparata usando una miscela di nitrato d&#39;argento (AgNO3), polivinilpirrolidone (PVP) e acqua (H 2 O). I campioni vengono poi modellati per irraggiamento con un 11-MHz laser a femtosecondi produzione di 50-fs impulsi. Durante l&#39;irradiazione, fotoriduzione di ioni argento è indotta tramite assorbimento non lineare, creando un aggregato di nanoparticelle di argento nella regione focale. Con questo approccio si creano modelli d&#39;argento incorporati in una matrice PVP drogato. Aggiunta traduzione in 3D della sampio si estende il patterning a tre dimensioni.

Acustoottico modulatore e filtri a densità neutra (Figura 1) permettono di controllare la quantità di energia depositata nel campione. Utilizzando una esposizione di 110 impulsi per voxel e 3 nJ per impulso, con la fase traducendo a 100 micron / sec, le strutture argento risultanti sono facilmente visibili attraverso l&#39;in-situ microscopio ottico. Bassi livelli di esposizione laser (riducendo l&#39;energia di impulso e / o il numero di impulsi) portano alle caratteristiche d&#39;argento pi...

Watch this Scientific Journal Video about A Method to Fabricate Disconnected Silver Nanostructures in 3D at JoVE.com

A Method to Fabricate Disconnected Silver Nanostructures in 3D

-Laser a femtosecondi diretta scrittura viene spesso utilizzato per creare tridimensionali (3D) in modelli di polimeri e bicchieri. Tuttavia, i metalli di patterning in 3D rimane una sfida. Si descrive un metodo per fabbricare nanostrutture argento incorporati all&#39;interno di una matrice polimerica utilizzando un laser a femtosecondi centrato a 800 nm.

Un metodo per fabbricare nanostrutture d&#39;argento disconnesse in 3D

The standard nanofabrication toolkit includes  techniques primarily aimed at creating 2D patterns in dielectric media. Creating  metal patterns on a ...

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13.7K Views.  Harvard University. -Laser a femtosecondi diretta scrittura viene spesso utilizzato per creare tridimensionali (3D) in modelli di polimeri e bicchieri. Tuttavia, i metalli di patterning in 3D rimane una sfida. Si descrive un metodo per fabbricare nanostrutture argento incorporati all'interno di una matrice polimerica utilizzando un laser a femtosecondi centrato a 800 nm.

Video: A Method to Fabricate Disconnected Silver Nanostructures in 3D

High-resolution, High-speed, Three-dimensional Video Imaging with Digital Fringe Projection Techniques

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses triangulation between matching points in two views of the same scene at different angles to compute depth.&#160;However, unlike a stereo-based method, DFP uses a digital video projector to replace one of the cameras1. The projector rapidly projects a known sinusoidal pattern onto the subject, and the surface of the subject distorts these patterns in the camera&#8217;s field of view. Three distorted patterns (fringe images) from the camera can be used to compute the depth using triangulation.
Unlike other 3D measurement methods, DFP techniques lead to systems that tend to be faster, lower in equipment cost, more flexible, and easier to develop.&#160;DFP systems can also achieve the same measurement resolution as the camera.&#160;For this reason, DFP and other digital structured light techniques have recently been the focus of intense research (as summarized in1-5). Taking advantage of DFP, the graphics processing unit, and optimized algorithms, we have developed a system capable of 30&#160;Hz 3D video data acquisition, reconstruction, and display for over 300,000 measurement points per frame6,7.&#160;Binary defocusing DFP methods can achieve even greater speeds8.
Diverse applications can benefit from DFP techniques. Our collaborators have used our systems for facial function analysis9, facial animation10, cardiac mechanics studies11, and fluid surface measurements, but many other potential applications exist.&#160;This video will teach the fundamentals of DFP techniques and illustrate the design and operation of a binary defocusing DFP system.

This video describes the fundamentals of digital fringe projection techniques, which provide dense 3D measurements of dynamically changing surfaces.&#160;It also demonstrates the design and operation of a high-speed binary defocusing system based on these techniques.

Digital fringe projection (DFP) techniques provide dense 3D measurements of dynamically changing surfaces.&#160;Like the human eyes and brain, DFP uses ...

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Ingegneria

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Valutare plasmoniche Trasporti in Current-carrying Argento Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

Writing and Low-Temperature Characterization of Oxide Nanostructures

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions. Oxide interfaces exhibit a wide range of properties that can be controlled include conduction, piezoelectric behavior, ferromagnetism, superconductivity and nonlinear optical properties. Recently, methods for controlling these properties at extreme nanoscale dimensions have been discovered and developed. Here are described explicit step-by-step procedures for creating LaAlO3/SrTiO3 nanostructures using a reversible conductive atomic force microscopy technique. The processing steps for creating electrical contacts to the LaAlO3/SrTiO3 interface are first described. Conductive nanostructures are created by applying voltages to a conductive atomic force microscope tip and locally switching the LaAlO3/SrTiO3 interface to a conductive state. A versatile nanolithography toolkit has been developed expressly for the purpose of controlling the atomic force microscope (AFM) tip path and voltage. Then, these nanostructures are placed in a cryostat and transport measurements are performed. The procedures described here should be useful to others wishing to conduct research in oxide nanoelectronics.

Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.

Scrittura e bassa temperatura Caratterizzazione di nanostrutture di ossido

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions.  Oxide ...

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

Tomografia a dispersione di energia dei raggi X per il 3D Elemental mappatura delle nanoparticelle individuali

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures

Layer semiconductors with easily processed two-dimensional (2D) structures exhibit indirect-to-direct bandgap transitions and superior transistor performance, which suggest a new direction for the development of next-generation ultrathin and flexible photonic and electronic devices. Enhanced luminescence quantum efficiency has been widely observed in these atomically thin 2D crystals. However, dimension effects beyond quantum confinement thicknesses or even at the micrometer scale are not expected and have rarely been observed. In this study, molybdenum diselenide (MoSe2) layer crystals with a thickness range of 6-2,700 nm were fabricated as two- or four-terminal devices. Ohmic contact formation was successfully achieved by the focused-ion beam (FIB) deposition method using platinum (Pt) as a contact metal. Layer crystals with various thicknesses were prepared through simple mechanical exfoliation by using dicing tape. Current-voltage curve measurements were performed to determine the conductivity value of the layer nanocrystals. In addition, high-resolution transmission electron microscopy, selected-area electron diffractometry, and energy-dispersive X-ray spectroscopy were used to characterize the interface of the metal&#8211;semiconductor contact of the FIB-fabricated MoSe2 devices. After applying the approaches, the substantial thickness-dependent electrical conductivity in a wide thickness range for the MoSe2-layer semiconductor was observed. The conductivity increased by over two orders of magnitude from 4.6 to 1,500 &#937;&#8722;1 cm&#8722;1, with a decrease in the thickness from 2,700 to 6 nm. In addition, the temperature-dependent conductivity indicated that the thin MoSe2 multilayers exhibited considerably weak semiconducting behavior with activation energies of 3.5-8.5 meV, which are considerably smaller than those (36-38 meV) of the bulk. Probable surface-dominant transport properties and the presence of a high surface electron concentration in MoSe2 are proposed. Similar results can be obtained for other layer semiconductor materials such as MoS2 and WS2.

We describe the approaches for the device fabrication and electrical characterization of molybdenum diselenide (MoSe2) layer semiconductor nanostructures with different thicknesses. In addition, the fabrication of ohmic contacts for MoSe2-layer nanocrystals by the focused-ion beam deposition method using platinum (Pt) as a contact metal is described.

Ohmico Fabrication contatto con una tecnica Focused Ion Beam-e caratterizzazione elettrica per strato semiconduttore Nanostrutture

Layer semiconductors with easily processed two-dimensional (2D) structures exhibit indirect-to-direct bandgap transitions and superior transistor ...

Integration of Light Trapping Silver Nanostructures in Hydrogenated Microcrystalline Silicon Solar Cells by Transfer Printing

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly known as plasmonic effects, play an important role. Research in this field has, however, been impeded owing to the difficulty of fabricating devices containing the desired functional metal nanostructures. In order to provide a viable strategy to this issue, we herein show a transfer printing-based approach that allows the quick and low-cost integration of designed metal nanostructures with a variety of device architectures, including solar cells. Nanopillar poly(dimethylsiloxane) (PDMS) stamps were fabricated from a commercially available nanohole plastic film as a master mold. On this nanopatterned PDMS stamps, Ag films were deposited, which were then transfer-printed onto block copolymer (binding layer)-coated hydrogenated microcrystalline Si (&#181;c-Si:H) surface to afford ordered Ag nanodisk structures. It was confirmed that the resulting Ag nanodisk-incorporated &#181;c-Si:H solar cells show higher performances compared to a cell without the transfer-printed Ag nanodisks, thanks to plasmonic light trapping effect derived from the Ag nanodisks. Because of the simplicity and versatility, further device application would also be feasible thorough this approach.

A viable transfer printing-based methodology to introduce plasmonic metal nanostructures in solar cells is described. Using nanopillar poly(dimethylsiloxane) stamps, an Ag-based ordered nanodisk array was integrated with standard hydrogenated microcrystalline Si solar cells, which led to improved device performances due to plasmonic light trapping.

Integrazione di luce Trapping Argento Nanostrutture in silicio microcristallino idrogenato celle solari tramite bonifico stampa

One of the potential applications of metal nanostructures is light trapping in solar cells, where unique optical properties of nanosized metals, commonly ...

Methods for Measuring the Orientation and Rotation Rate of 3D-printed Particles in Turbulence

Experimental methods are presented for measuring the rotational and translational motion of anisotropic particles in turbulent fluid flows. 3D printing technology is used to fabricate particles with slender arms connected at a common center. Shapes explored are crosses (two perpendicular rods), jacks (three perpendicular rods), triads (three rods in triangular planar symmetry), and tetrads (four arms in tetrahedral symmetry). Methods for producing on the order of 10,000 fluorescently dyed particles are described. Time-resolved measurements of their orientation and solid-body rotation rate are obtained from four synchronized videos of their motion in a turbulent flow between oscillating grids with R&#955; = 91. In this relatively low-Reynolds number flow, the advected particles are small enough that they approximate ellipsoidal tracer particles. We present results of time-resolved 3D trajectories of position and orientation of the particles as well as measurements of their rotation rates.

We use 3D printing to fabricate anisotropic particles in the shapes of jacks, crosses, tetrads, and triads, whose alignments and rotations in turbulent fluid flow can be measured from multiple simultaneous video images.

Metodi per misurare l&#39;orientamento e rotazione Tasso di particelle in turbolenza 3D-stampati

Experimental methods are presented for measuring the rotational and translational motion of anisotropic particles in turbulent fluid flows. 3D printing ...

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of stretchable electronic devices is the preparation of stretchable conductors with great mechanical stability. In this study, we developed a simple fabrication method to chemically solder the contact points between silver nanowire (AgNW) networks. AgNW nanomesh was first deposited on a glass slide via spray coating method. A reactive ink composed of silver nanoparticle (AgNPs) precursors was applied over the spray coated AgNW thin films. After heating for 40 min, AgNPs were preferentially generated over the nanowire junctions to solder the AgNW nanomesh, and reinforced the conducting network. The chemically modified AgNW thin film was then transferred to polyurethane (PU) substrates by casting method. The soldered AgNW thin films on PU exhibited no obvious change in electrical conductivity under stretching or rolling process with elongation strains up to 120%.

A simple synthesis method is used to chemically solder silver nanowire thin film to fabricate highly stretchable and conductive metal conductors.

Un metodo di fabbricazione di conduttori è molto estensibile con argento Nanofili

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

Le sfide in reologico Caratterizzazione di sospensioni altamente concentrato - un caso di studio per la serigrafia paste d&#39;argento

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D materials is still in nascent stages, scientists cannot fully rely on traditional semiconductor techniques for related research. Delicate processes from locating the materials to electrode definition need to be well controlled. In this article, a universal fabrication protocol required in manufacturing nanoscale electronics, such as 2D quasi-heterojunction bipolar transistors (Q-HBT), and 2D back-gated transistors are demonstrated. This protocol includes the determination of material position, electron beam lithography (EBL), metal electrode definition, et al. A step by step narrative of the fabrication procedures for these devices are also presented. Furthermore, results show that each of the fabricated devices has achieved high performance with high repeatability. This work reveals a comprehensive description of process flow for preparing 2D nano-electronics, enables the research groups to access this information, and pave the way toward future electronics.

The article aims to introduce a standard and reliable fabrication procedure for the development of future low dimensional nanoelectronics.

Un metodo Standard e affidabile per fabbricare nanoelettronica bidimensionale

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D ...