This work was carried out in the framework of the project &#8220;MIRAGE,&#8221; funded by the European Commission within the FP7 program.

1. assisté LIFT-flip-chip Bonding NOTE: Il ya trois étapes impliquées dans la réalisation des assemblages flip-chip assisté LIFT-, à savoir-micro-supplantation des substrats en utilisant la technique de LIFT, fixer les puces optoélectroniques aux substrats tombé utilisant thermo-compression procédé de collage flip-chip, et enfin encapsulation des assemblages collés. Chacune de ces étapes est discutée dans les sections suivantes: <ol><li> Micro-choc utilisant LIFT: <ol><li> Pour la préparation des donateurs, déposer un film mince du matériau donneur sur un substrat de support transparent au laser. Pour cette expérience, évaporer une couche épaisse de 200 nm d&#39;indium métal sur le dessus du verre substrat de support avec les dimensions: 2 pouces de diamètre x 0,05 cm d&#39;épaisseur. REMARQUE: la méthode de préparation des bailleurs de fonds dépend de la phase du matériau donneur, par exemple, utiliser l&#39;évaporation et la pulvérisation des matériaux de donateurs en phase solide et de spin-coating et le médecin à roues alignées pour en phase liquide donateurss. </li><li> Pour la préparation de récepteur, utiliser des substrats de verre avec des dimensions de 5 x 5 x 0,07 cm 3 que les récepteurs. Motif ces substrats avec les plots de contact métalliques pour lier la puce OE et fan-out sonder structures utilisant la photolithographie. Pour cette expérience, épais plots de Ni-Au modèle 4 um et fan-out sonder pistes sur des substrats du récepteur de verre. </li><li> Ensuite, placez le donneur en contact avec le récepteur et monter l&#39;ensemble des donateurs récepteur sur une platine de translation XY contrôlé par ordinateur. NOTE: En fonction de la phase du matériau donneur (par exemple, solide (indium) ou liquide (encre / coller)) et son épaisseur, le donateur et les substrats du récepteur sont placés à une séparation optimale qui peut être facilement contrôlé (par exemple, par utilisant des entretoises métalliques). </li><li> Focaliser le faisceau laser incident à l&#39;interface support-donateurs employant un objectif de 160 mm de focale et de balayer le faisceau (20 um de taille de spot) à travers le Substrat donneure pour transférer donateurs micro-bosses sur le récepteur obligataires tampons. Utilisez une source laser picoseconde de 355 nm de longueur d&#39;onde et 12 durée d&#39;impulsion psec LIFT bosses indium sur le récepteur obligataires tampons à une fluence de 270 mJ / cm 2. REMARQUE: Les propriétés laser tels que l&#39;énergie, non. d&#39;impulsions, la hauteur de l&#39;objectif, les coordonnées de l&#39;emplacement précis sur le substrat du récepteur pour l&#39;impression donateurs micro-chocs et le motif désiré être transférés sont contrôlés avec précision par un programme informatique. Paramètres expérimentaux clés (par exemple, le transfert fluence) doivent être optimisés en cas d&#39;utilisation d&#39;une autre source laser. </li><li> Pour bosses épaisses déplacer le donneur à un endroit frais et répétez l&#39;étape 1.1.4 à plusieurs reprises. Par exemple, répétez l&#39;étape 1.1.4 six fois pour obtenir une pile de 6 billes d&#39;indium imprimés sur le dessus de l&#39;autre pour cette expérience. La dernière levée bosses ont une hauteur moyenne de ~ 1,5 um et un diamètre de 20 pm (Figure 2). NOTE: Pour ces expériments du profil de surface et l&#39;épaisseur des bosses ont été mesurées en utilisant un profilomètre optique. On a examiné ce que les bosses ont une morphologie convexe / dôme avec une épaisseur moyenne de 1,5 pm, en moyenne sur le diamètre de la bosse (comme indiqué sur la figure 3 jaune). La raison de ceci est due au fait que le donneur fondu dans la zone irradiée par laser et la pastille re-transféré ensuite solidifiée après avoir atteint la surface de réception (indium a un point de fusion bas). L&#39;avantage de ceci est que cela se traduit par une bonne adhérence de la bosse imprimé à des plots de contact VCSEL. </li></ol></li><li> Chip au substrat soudage par thermo-compression (figures 4-6): <ol><li> Utilisez un semi-automatique flip-chip colle pour coller les puces optoélectroniques aux substrats tombé. </li><li> Chargez le récepteur heurté et la puce à coller sur leurs plaques à vide respectives de la colle. Placez la puce dans une position inversée, ce est à dire, avec sa zone fac actifVERS LE HAUT. </li><li> Utilisez un outil de pick-up approprié et l&#39;aligner sur le centre de la puce. Utilisez un outil en forme d&#39;aiguille, comme indiqué sur la Figure 5. Ensuite, choisissez la puce en utilisant cet outil de prise en charge. </li><li> Alignez les puces obligataires tampons avec les plots de contact correspondants sur le substrat du récepteur en utilisant un système caméra-alignement. </li><li> Une fois aligné lieu la puce sur le substrat. </li><li> Appliquez de la chaleur (~ 200 ° C) et de pression (12,5 gf / bosse) simultanément de réaliser la puce au substrat interconnexions électriques et mécaniques. </li></ol></li><li> Encapsulation des assemblages collés (figures 4-6): <ol><li> Distribuer un adhésif optiquement transparent sur les bords de l&#39;assemblage collé en utilisant une aiguille de seringue. L&#39;encapsulation augmente la fiabilité mécanique des assemblages collés. Utilisez un seul composant adhésif à durcissement UV tels que NOA 86 pour encapsuler les puces collées. </li><li> Durcir l&#39;adhésif à l&#39;aide d&#39;une lampe UV pendant environ 30 sec. </li></ol></li></ol> 2. La caractérisation des agglomérés à cavité verticale lasers à émission de surface (VCSEL) NOTE: Après la fabrication de la prochaine étape consiste à évaluer la performance électro-optique des assemblages collés. Les courbes courant-tension-lumière (LIV) des appareils sont enregistrées post collage utilisant une station de sonde. Les étapes suivantes sont impliqués pour le test: <ol><li> Placez le flip-chip dispositif collé sur une scène transparente sur mesure. L&#39;étape a un trou percé dans le centre pour un accès facile à la lumière émise par les VCSEL. </li><li> Placer un photodétecteur (PD) au-dessous de l&#39;étage transparent et aligner sa surface active de la puce de stockage au moyen d&#39;un microscope. </li><li> Positionner avec précision les aiguilles de sondage sur le Ni-Au sonder plaquettes en utilisant un microscope. </li><li> Injecter jusqu&#39;à 10 mA de courant et mesurer la chute de tension aux bornes du VCSEL et la lumière émise par celle-ci en utilisant un / tension unité source de courant et un compteur wattmètre restivement. </li></ol>

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The authors have nothing to disclose.

Dans cet article, nous avons démontré thermo-compression flip-chip collage des puces VCSEL simples en utilisant une technique d&#39;écriture directe basé sur un laser appelé LIFT. Les étapes de fabrication assemblage impliqués impression des micro-bosses d&#39;indium sur les plots de contact de substrat en utilisant la technique de LIFT. Cela a été suivi par thermo-compression flip-chip collage des puces VCSEL aux substrats heurté et enfin leur encapsulation. Électriques, optiques...

Induite par laser transfert vers l&#39;avant (LIFT) est une écriture directe additif procédé de fabrication polyvalent pour la définition du motif en une seule étape et de transfert de matériel avec micron et sub-micronique résolution. Dans cet article, nous présentons l&#39;utilisation de LIFT comme une technique pour cogner flip-chip emballage de cavité verticale émettant surface lasers VCSEL () sur une puce échelle. Flip-puce est une technologie clé dans l&#39;emballage et l&#39;intégration de (OE) composants électroniques et optoélectroniques système. Afin de parvenir à une intégration dense de composants liaison à pas fin est essentiel. Bien que la liaison à pas fin a été démontré par certaines des techniques standard, mais il ya un vide en termes de combiner ensemble les autres caractéristiques importantes telles que la flexibilité, la rentabilité, la vitesse, la précision et à faible température de traitement. Afin de répondre à ces exigences, nous démontrons procédé de collage assisté LIFT-thermo-compression pour bien collage de hauteur des composants OE. En LIFT, un film mince du matériau à imprimer (dénommé donneur) est déposée sur une face d&#39;un substrat de support transparent au laser (dénommé le transporteur). La figure 1 illustre le principe de base de cette technique. Une impulsion laser incident d&#39;une intensité suffisante est alors concentré à l&#39;interface support-donneur qui fournit la force de propulsion requise pour transmettre transférer le pixel de donneur de la zone irradiée sur un autre substrat (dénommé récepteur) placé à proximité immédiate. LIFT a été signalée pour la première en 1986 par Bohandy comme une technique pour imprimer des lignes de cuivre de taille micronique pour réparer endommagés photo-masques 3. Depuis sa première démonstration de cette technique a suscité un intérêt important en tant que technologie de fabrication de micro-nano pour motifs contrôlée et l&#39;impression d&#39;une large gamme de matériaux tels que la céramique 4, 5, NTC QDs 6, 7 cellules vivantes, graphiqueène 8, pour diverses applications telles que les bio-capteurs 9, OLED 10, 11 composants optoélectroniques, capteurs plasmoniques 12, bio-électronique 13 et collage 14,15 flip-chip. LIFT offre plusieurs avantages par rapport aux techniques de supplantation et de liaison flip-chip existants tels que la simplicité, la rapidité, la flexibilité, la rentabilité, de haute résolution et la précision des flip-chip emballage de composants OE.

<table border="0" cellpadding="0" cellspacing="0" width="663">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:161px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Laser source</td>
			<td style="width:161px;">3D MicroMac (3DMM)</td>
			<td style="width:119px;">2912-295</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Photodetector</td>
			<td style="width:161px;">Newport&#160;</td>
			<td style="width:119px;">818 series</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Source measurement unit</td>
			<td style="width:161px;">Keithley&#160;</td>
			<td style="width:119px;">2401</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Power meter</td>
			<td style="width:161px;">Newport&#160;</td>
			<td style="width:119px;">1930</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Underfill</td>
			<td style="width:161px;">Norlands</td>
			<td style="width:119px;">NOA 86</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">UV lamp</td>
			<td style="width:161px;">Omnicure</td>
			<td style="width:119px;">Series 1000 UV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Probe station</td>
			<td style="width:161px;">Cascade Microtech</td>
			<td style="width:119px;">model 42</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Flip-chip bonder</td>
			<td style="width:161px;">Dr. Tresky</td>
			<td style="width:119px;">T-320 X</td>
			<td></td>
		</tr>
	</tbody>
</table>

laser-induced forward transfer for flip-chip packaging of single dies

Flip-chip (FC) l&#39;emballage est une technologie clé pour la réalisation de haute performance, ultra-circuits miniaturisés et à haute densité dans l&#39;industrie micro-électronique. Dans cette technique, la puce et / ou le substrat est heurté et les deux sont liés par ces bosses conductrices. De nombreuses techniques ont été développées de supplantation et de recherches intensives depuis l&#39;introduction de la technologie FC en 1960 comme une impression au pochoir, stud bumping, l&#39;évaporation et chimique / galvanoplastie 2. Malgré les progrès que ces méthodes ont fait, ils souffrent tous d&#39;un ou plus d&#39;un des inconvénients qui doivent être abordés tels que le coût, les étapes complexes de traitement, les températures élevées de traitement, temps de fabrication et surtout le manque de flexibilité. Dans cet article, nous démontrons une bosse technique basée laser simple et rentable formant connu sous le nom de transfert avant induite par laser (LIFT) 3. En utilisant la technique de LIFT une large gamme de matériaux de bosse peut be imprimés en une seule étape avec une grande flexibilité, haute vitesse et la précision à la température ambiante. En outre, LIFT permet de supplantation et liaison vers le bas la carte à puce à l&#39;échelle, ce qui est essentiel pour la fabrication de circuits ultra-miniature.

La figure 7 montre une courbe typique de LIV qui a été enregistrée à partir de l&#39;un des flip-chip de nombreuses puces collées VCSEL. Un bon match entre la puissance optique mesurée au fournisseur cité valeurs indiquées bon fonctionnement des dispositifs liés post collage. Les courbes ont également été enregistrées priorité et post-encapsulation et sur ​​la comparaison on a vérifié que le produit d&#39;enrobage avait aucun effet sur ​​la fonctionnalité de la puce (comme repr?...

Watch this Scientific Journal Video about Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies at JoVE.com

Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies

Nous démontrons l&#39;utilisation du transfert (LIFT) Forward technique induite par laser pour l&#39;assemblage flip-chip de composants optoélectroniques. Cette approche fournit une, rentable, à basse température simple, solution rapide et flexible pour pas fin de supplantation et de collage sur la puce à l&#39;échelle pour atteindre circuits à haute densité pour des applications optoélectroniques.

Induite par laser transfert vers l&#39;avant pour Flip-chip emballage de Dies simples

Flip-chip (FC) packaging is a key technology for realizing high performance, ultra-miniaturized and high-density circuits in the micro-electronics ...

laser-induced-forward-transfer-for-flip-chip-packaging-of-single-dies

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JoVE Journal

Engineering

12.2K vues.  Ghent University-imec.  Nous démontrons l'utilisation du transfert (LIFT) Forward technique induite par laser pour l'assemblage flip-chip de composants optoélectroniques. Cette approche fournit une, rentable, à basse température simple, solution rapide et flexible pour pas fin de supplantation et de collage sur la puce à l'échelle pour atteindre circuits à haute densité pour des applications optoélectroniques. 

Vidéo: Laser-induced Forward Transfer for Flip-chip Packaging of Single Dies

Compact Quantum Dots for Single-molecule Imaging

Single-molecule imaging is an important tool for understanding the mechanisms of biomolecular function and for visualizing the spatial and temporal heterogeneity of molecular behaviors that underlie cellular biology 1-4. To image an individual molecule of interest, it is typically conjugated to a fluorescent tag (dye, protein, bead, or quantum dot) and observed with epifluorescence or total internal reflection fluorescence (TIRF) microscopy. While dyes and fluorescent proteins have been the mainstay of fluorescence imaging for decades, their fluorescence is unstable under high photon fluxes necessary to observe individual molecules, yielding only a few seconds of observation before complete loss of signal. Latex beads and dye-labeled beads provide improved signal stability but at the expense of drastically larger hydrodynamic size, which can deleteriously alter the diffusion and behavior of the molecule under study.
Quantum dots (QDs) offer a balance between these two problematic regimes. These nanoparticles are composed of semiconductor materials and can be engineered with a hydrodynamically compact size with exceptional resistance to photodegradation 5. Thus in recent years QDs have been instrumental in enabling long-term observation of complex macromolecular behavior on the single molecule level. However these particles have still been found to exhibit impaired diffusion in crowded molecular environments such as the cellular cytoplasm and the neuronal synaptic cleft, where their sizes are still too large 4,6,7.
Recently we have engineered the cores and surface coatings of QDs for minimized hydrodynamic size, while balancing offsets to colloidal stability, photostability, brightness, and nonspecific binding that have hindered the utility of compact QDs in the past 8,9. The goal of this article is to demonstrate the synthesis, modification, and characterization of these optimized nanocrystals, composed of an alloyed HgxCd1-xSe core coated with an insulating CdyZn1-yS shell, further coated with a multidentate polymer ligand modified with short polyethylene glycol (PEG) chains (Figure 1). Compared with conventional CdSe nanocrystals, HgxCd1-xSe alloys offer greater quantum yields of fluorescence, fluorescence at red and near-infrared wavelengths for enhanced signal-to-noise in cells, and excitation at non-cytotoxic visible wavelengths. Multidentate polymer coatings bind to the nanocrystal surface in a closed and flat conformation to minimize hydrodynamic size, and PEG neutralizes the surface charge to minimize nonspecific binding to cells and biomolecules. The end result is a brightly fluorescent nanocrystal with emission between 550-800 nm and a total hydrodynamic size near 12 nm. This is in the same size range as many soluble globular proteins in cells, and substantially smaller than conventional PEGylated QDs (25-35 nm).

We describe the preparation of colloidal quantum dots with minimized hydrodynamic size for single-molecule fluorescence imaging. Compared to conventional quantum dots, these nanoparticles are similar in size to globular proteins and are optimized for single-molecule brightness, stability against photodegradation, and resistance to nonspecific binding to proteins and cells.

Compact points quantiques pour une seule molécule d&#39;imagerie

Single-molecule imaging is an important tool for  understanding the mechanisms of biomolecular function and for visualizing the  spatial and temporal ...

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Ingénierie

Analysis of Contact Interfaces for Single GaN Nanowire Devices

Single GaN nanowire (NW) devices fabricated on SiO2 can exhibit a strong degradation after annealing due to the occurrence of void formation at the contact/SiO2 interface. This void formation can cause cracking and delamination of the metal film, which can increase the resistance or lead to a complete failure of the NW device. In order to address issues associated with void formation, a technique was developed that removes Ni/Au contact metal films from the substrates to allow for the examination and characterization of the contact/substrate and contact/NW interfaces of single GaN NW devices. This procedure determines the degree of adhesion of the contact films to the substrate and NWs and allows for the characterization of the morphology and composition of the contact interface with the substrate and nanowires. This technique is also useful for assessing the amount of residual contamination that remains from the NW suspension and from photolithographic processes on the NW-SiO2 surface prior to metal deposition. The detailed steps of this procedure are presented for the removal of annealed Ni/Au contacts to Mg-doped GaN NWs on a SiO2 substrate.

A technique was developed that removes Ni/Au contact metal films from their substrate to allow for the examination and characterization of the contact/substrate and contact/NW interfaces of single GaN nanowire devices.

Analyse des Interfaces de contact pour GaN appareils nanofils

Single GaN nanowire (NW) devices fabricated on SiO2 can exhibit  a strong degradation after annealing due to the  occurrence of void formation at the ...

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement is used. Here we operate a Nd:YAG laser at a frequency of 10 Hz at the fundamental wavelength of 1,064 nm. The 14 nsec pulses with anenergy of 190 mJ/pulse are focused to a 50 &#181;m spot size to generate a plasma from optical breakdown or laser ablation in air. The microplasma is imaged onto the entrance slit of a 0.6 m spectrometer, and spectra are recorded using an 1,800 grooves/mm grating an intensified linear diode array and optical multichannel analyzer (OMA) or an ICCD. Of interest are Stark-broadened atomic lines of the hydrogen Balmer series to infer electron density. We also elaborate on temperature measurements from diatomic emission spectra of aluminum monoxide (AlO), carbon (C2), cyanogen (CN), and titanium monoxide (TiO).
The experimental procedures include wavelength and sensitivity calibrations. Analysis of the recorded molecular spectra is accomplished by the fitting of data with tabulated line strengths. Furthermore, Monte-Carlo type simulations are performed to estimate the error margins. Time-resolved measurements are essential for the transient plasma commonly encountered in LIBS.

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown

Time-resolved atomic and diatomic molecular species are measured using LIBS. The spectra are collected at various time delays following the generation of optical breakdown plasma with Nd:YAG laser radiation&#160;and are analyzed to infer electron density and temperature.

Mesure et analyse de l&#39;hydrogène atomique et moléculaire diatomique AlO, C<sub&gt; 2</sub&gt;, CN, et TiO Spectra après une rupture optique induite par laser

In this work, we present time-resolved measurements of atomic and diatomic spectra following laser-induced optical breakdown. A typical LIBS arrangement ...

Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle's Mapping and Quantification in Organ Tissue

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) performed on thin sections of rodent tissues: kidneys and tumor, allows the detection of inorganic elements such as (i) Na, Ca, Cu, Mg, P, and Fe, naturally present in the body and (ii) Si and Gd, detected after the injection of gadolinium-based nanoparticles. The animals were euthanized 1&#160;to 24 hr&#160;after intravenous injection of particles. A two-dimensional scan of the sample, performed using a motorized micrometric 3D-stage, allowed the infrared laser beam exploring the surface with a lateral resolution less than 100 &#956;m. Quantitative chemical images of Gd element inside the organ were obtained with sub-mM sensitivity. LIBS offers a simple and robust method to study the distribution of inorganic materials without any specific labeling. Moreover, the compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of the same biological tissue with different types of response:&#160;elemental, molecular, or cellular.

Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle&#039;s Mapping and Quantification in Organ Tissue

Laser-induced breakdown spectroscopy performed on thin organ and tumor tissue successfully detected natural elements and artificially injected gadolinium (Gd), issued from Gd-based nanoparticles. Images of chemical elements reached a resolution of 100 &#956;m and quantitative sub-mM sensitivity. The compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of a same biological tissue.

Induite par laser Répartition Spectroscopy: Une nouvelle approche pour la cartographie et la quantification de nanoparticules dans les tissus d&#39;organes

Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) ...

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by quantum mechanical effects such as tunneling through single dopants, scattering via interface defects, and discrete trap charge states. However, progress in silicon technology has shown that these phenomena can be harnessed and exploited for a new class of quantum-based electronics. Among others, multi-layer-gated silicon metal-oxide-semiconductor (MOS) technology can be used to control single charge or spin confined in electrostatically-defined quantum dots (QD). These QD-based devices are an excellent platform for quantum computing applications and, recently, it has been demonstrated that they can also be used as single-electron pumps, which are accurate sources of quantized current for metrological purposes. Here, we discuss in detail the fabrication protocol for silicon MOS QDs which is relevant to both quantum computing and quantum metrology applications. Moreover, we describe characterization methods to test the integrity of the devices after fabrication. Finally, we give a brief description of the measurement set-up used for charge pumping experiments and show representative results of electric current quantization.

The fabrication process and experimental characterization techniques relevant to single-electron pumps based on silicon metal-oxide-semiconductor quantum dots are discussed.

Silicium métal-oxyde-semiconducteur Quantum Dots pour le pompage mono-électronique

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by ...

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.

Intégration de la Lumière de piégeage argent Nanostructures dans hydrogénée microcristalline cellules solaires en silicium par impression par transfert

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

Laser-induced Forward Transfer of Ag Nanopaste

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of these processes such as inkjet3 and laser-induced forward transfer (LIFT)4 have become increasingly popular as interest in printable electronics and maskless patterning has grown. These additive manufacturing processes are inexpensive, environmentally friendly, and well suited for rapid prototyping, when compared to more traditional semiconductor processing techniques. While most direct-write processes are confined to two-dimensional structures and cannot handle materials with high viscosity (particularly inkjet), LIFT can transcend both constraints if performed properly. Congruent transfer of three dimensional pixels (called voxels), also referred to as laser decal transfer (LDT)5-9, has recently been demonstrated with the LIFT technique using highly viscous Ag nanopastes to fabricate freestanding interconnects, complex voxel shapes, and high-aspect-ratio structures. In this paper, we demonstrate a simple yet versatile process for fabricating a variety of micro- and macroscale Ag structures. Structures include simple shapes for patterning electrical contacts, bridging and cantilever structures, high-aspect-ratio structures, and single-shot, large area transfers using a commercial digital micromirror device (DMD) chip.

We demonstrate the use of the Laser-induced forward transfer technique (LIFT) for the printing of high-viscosity Ag paste. This technique offers a simple, low temperature, robust process for non-lithographically printing microscale 2D and 3D structures.

induite par laser-Transfer Forward de Ag nanopâte

Over the past decade, there has been much development of non-lithographic methods1-3 for printing metallic inks or other functional materials. Many of ...

Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation

We present a protocol for fabricating 1-D Photonic Crystal (PhC) cavities on subwavelength-diameter tapered optical fibers, optical nanofibers, using femtosecond laser-induced ablation. We show that thousands of periodic nano-craters are fabricated on an optical nanofiber by irradiating with just a single femtosecond laser pulse. For a typical sample, periodic nano-craters with a period of 350 nm and with diameter gradually varying from 50 - 250 nm over a length of 1 mm are fabricated on a nanofiber with diameter around 450 - 550 nm. A key aspect of such a nanofabrication is that the nanofiber itself acts as a cylindrical lens and focuses the femtosecond laser beam on its shadow surface. Moreover, the single-shot fabrication makes it immune to mechanical instabilities and other fabrication imperfections. Such periodic nano-craters on nanofiber, act as a 1-D PhC and enable strong and broadband reflection while maintaining the high transmission out of the stopband. We also present a method to control the profile of the nano-crater array to fabricate apodized and defect-induced PhC cavities on the nanofiber. The strong confinement of the field, both transverse and longitudinal, in the nanofiber-based PhC cavities and the efficient integration to the fiber networks, may open new possibilities for nanophotonic applications and quantum information science.

We present a protocol for fabricating 1-D photonic crystal cavities on subwavelength diameter silica fibers (optical nanofibers) using femtosecond laser-induced ablation.

Fabrication de 1-D Cristal Photonique Cavity sur un nanofibres utilisant Ablation laser femtoseconde induite

We present a protocol for fabricating 1-D Photonic Crystal (PhC) cavities on subwavelength-diameter tapered optical fibers, optical nanofibers, using ...

Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light scattering from intraocular lenses (IOLs) using goniophotometer principles. This protocol describes the SLSP platform and how it employs a 360&#176; rotational photodetector sensor that is scanned around an IOL sample while recording the intensity and location of scattered light as it passes through the IOL medium. The SLSP platform can be used to predict, non-clinically, the propensity for current and novel IOL designs and materials to induce light scatter. Non-clinical evaluation of light scattering properties of IOLs can significantly reduce the number of patient complaints related to unwanted glare, glistening, optical defects, poor image quality, and other phenomena associated with the unintended light scattering. Future studies should be conducted to correlate SLSP data with clinical results to help identify which measured light scatter is most problematic for patients that have undergone cataract surgery subsequent to IOL implantation.

Scanning Light Scattering Profiler SLPS Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

This protocol describes the scanning light scattering profiler (SLSP) that enables the full-angle quantitative evaluation of forward and backward scattering of light from intraocular lenses (IOLs) using goniophotometer principles.

Méthodologie basée sur le Profiler de diffusion de lumière de balayage (SLPS) pour évaluer quantitativement la diffusion de lumière vers l&#39;avant et vers l&#39;arrière à partir de lentilles intraoculaires

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light ...

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new techniques capable of characterizing their dynamics. Investigating single dopants requires sub-nanometer spatial resolution, which motivates the use of scanning tunneling microscopy (STM). However, conventional STM is limited to millisecond temporal resolution. Several methods have been developed to overcome this shortcoming, including all-electronic time-resolved STM, which is used in this study to examine dopant dynamics in silicon with nanosecond resolution. The methods presented here are widely accessible and allow for local measurement of a wide variety of dynamics at the atomic scale. A novel time-resolved scanning tunneling spectroscopy technique is presented and used to efficiently search for dynamics.

We demonstrate an all-electronic method to observe nanosecond-resolved charge dynamics of dopant atoms in silicon with a scanning tunneling microscope.

Entièrement électronique résolue en nanosecondes Tunneling microscope à balayage : Faciliter l’Investigation de la dynamique de Charge unique de Dopant

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new ...