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

1. Levante asistida flip-chip Bonding NOTA: Hay tres etapas involucradas en la realización de las asambleas flip-chip LIFT asistida, es decir, micro-golpes de los sustratos utilizando la técnica LIFT, adjuntando los chips optoelectrónicos a los sustratos chocaron con el método de unión flip-chip termo-compresión, y finalmente encapsulación de las asambleas de servidumbre. Cada una de estas etapas se discute en las siguientes secciones: <ol><li> Micro-chocar usando LIFT: <ol><li> Para la preparación de los donantes, depositar una película delgada de material donante en un sustrato portador transparente al láser. Para este experimento, se evapora una gruesa película de 200 nm de metal de indio en la parte superior del sustrato de soporte de vidrio con dimensiones: espesor de 2 pulgadas de diámetro x 0,05 cm. NOTA: método de preparación de los donantes depende de la fase del material del donante, por ejemplo, utilizar la evaporación y pulverización catódica para los materiales donantes en fase sólida y spin-recubrimiento y médico-Perfilado de donante en fase líquidas. </li><li> Para la preparación del receptor, utilizar sustratos de vidrio con dimensiones de 5 x 5 x 0,07 cm 3 como los receptores. Patrón de estos sustratos con las almohadillas de contacto metálicos para unir el chip de la OE y fan-out sondeo estructuras usando fotolitografía. Para este experimento, patrón de 4 m de espesor terminales de unión Ni-Au y fan-out sondeo pistas sobre sustratos del receptor de vidrio. </li><li> Luego, coloque el donante en contacto con el receptor y montar el conjunto donante-receptor en una etapa de traslación XY controlada por ordenador. NOTA: En función de la fase del material donante (por ejemplo, sólido (indio) o líquido (tinta / pegar)) y su espesor, el donante y los sustratos del receptor se colocan en una separación óptima que puede ser controlado fácilmente (por ejemplo, usando espaciadores metálicos). </li><li> Enfocar el haz láser incidente en la interfase portador de donantes que emplea una lente de objetivo de 160 mm de distancia focal y explorar el haz (20 micras tamaño del punto) a través del substrat donantee para la transferencia de donantes micro-protuberancias en el receptor de bonos-pads. Utilice una fuente de láser de picosegundos de longitud de onda de 355 nm y 12 duración del pulso psec a LEVANTAR golpes de indio en el receptor de bonos-pads a una fluencia de 270 mJ / cm2. NOTA: Las propiedades de láser, como la energía, no. de legumbres, altura lente objetivo, las coordenadas de su ubicación exacta en el sustrato del receptor de donantes impresión micro-golpes y el modelo deseado para ser transferidos son controlados con precisión mediante un programa informático. Parámetros experimentales clave (por ejemplo, la transferencia de fluencia) necesitan ser optimizado en caso de utilizar otra fuente láser. </li><li> Para protuberancias gruesas mover el donante a un área fresca y repita el paso 1.1.4 varias veces. Por ejemplo, repita el paso 1.1.4 seis veces para obtener una pila de 6 golpes de indio impresos en la parte superior de uno al otro para este experimento. La final levantó pápulas tienen una altura promedio de ~ 1,5 my un diámetro de 20 mm (Figura 2). NOTA: Para estos experimpadres el perfil de la superficie y el espesor de las protuberancias se midieron usando un perfilómetro óptico. Fue examinado si los golpes tenían una morfología convexa / cúpula con un espesor medio de 1,5 micras, de media sobre el diámetro golpe (como se marca amarilla en la Figura 3). La razón de esto se atribuye al hecho de que el donante se fundió en la zona de láser irradiado y el sedimento transferido luego re-solidificó al llegar a la superficie del receptor (indio tiene un punto de fusión bajo). La ventaja de esto es que resulta en una buena adherencia de la protuberancia impresa a las almohadillas de contacto VCSEL. </li></ol></li><li> Chip al sustrato unión termo-compresión (Figuras 4-6): <ol><li> Utilice una semiautomática bonder flip-chip para la unión de los chips optoelectrónicos a los sustratos golpeado. </li><li> Cargue el receptor golpeado y el chip para estar unidos en sus respectivas placas de vacío del dispositivo de adhesión. Coloque el chip en una posición invertida, es decir, con su área activa faclas marchas. </li><li> Utilice una herramienta de recogida adecuado y corresponda con el centro del chip. Utilice una herramienta en forma de aguja, como se muestra en la Figura 5. A continuación, elija el chip utilizando esta herramienta de recogida. </li><li> Alinear los chips de bonos-pads con las almohadillas de contacto correspondientes en el sustrato receptor mediante un sistema de cámara-alineación. </li><li> Una vez alineado lugar el chip sobre el sustrato. </li><li> Aplicar calor (~ 200 ° C) y presión (12,5 gf / golpe) simultáneamente a darse cuenta de chip al sustrato interconexiones eléctricas y mecánicas. </li></ol></li><li> La encapsulación de los conjuntos de servidumbre (Figuras 4-6): <ol><li> Dispensar un adhesivo ópticamente transparente alrededor de los bordes del conjunto unido utilizando una aguja de jeringa. La encapsulación aumenta la fiabilidad mecánica de los conjuntos unidos. Utilice un único adhesivo curable UV componente como NOA 86 para encapsular los chips unidos. </li><li> Curar el adhesivo usando una lámpara UV para ~ 30 seg. </li></ol></li></ol> 2. Caracterización de los Vertical-cavidad láseres de emisión superficial en condiciones de servidumbre (VCSEL) NOTA: Después de la fabricación el siguiente paso es evaluar el rendimiento electro-óptica de los conjuntos de servidumbre. Los-corriente-tensión de luz (LIV) curvas de los dispositivos se registran después de la unión usando una estación de sonda. Los siguientes pasos están involucrados para la prueba: <ol><li> Coloque el flip-chip dispositivo unido a un escenario transparente a medida. La etapa tiene un agujero perforado en el centro para facilitar el acceso a la luz emitida por los VCSELs. </li><li> Coloque un fotodetector (PD) debajo del escenario transparente y alinear su área activa con el chip unido usando un microscopio. </li><li> Colocar con precisión las agujas de sondeo en el Ni-Au sondeo almohadillas con un microscopio. </li><li> Inyectar hasta 10 mA de corriente y medir la caída de voltaje a través del VCSEL y la luz emitida por éste utilizando un / unidad de fuente de voltaje de corriente-metro y un metro de potencia restivamente. </li></ol>

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The authors have nothing to disclose.

En este trabajo, hemos demostrado termo-compresión flip-chip pegado de virutas VCSEL individuales utilizando una técnica de escritura directa con láser basado llamado LIFT. Las etapas de fabricación montaje involucrados impresión de los micro-golpes de indio en las zonas de contacto sustrato utilizando la técnica de ascensor. Esto fue seguido por termo-compresión flip-chip de unión de los chips de VCSEL a los sustratos golpeado y, finalmente, su encapsulación. Eléctrico, óptico y ...

Laser-inducida Transferencia Forward (LIFT) es un directo escribir método de fabricación aditiva versátil para definición del patrón de un solo paso y de transferencia de material con micrones y sub micrones de resolución. En este trabajo, nos informe el uso de LIFT como técnica chocar para el envasado flip-chip de cavidad vertical de emisión de superficie láseres (VCSEL) en una escala de chip. Flip-chip es una tecnología clave en envases sistema y la integración de (OE) componentes electrónicos y optoelectrónicos. Con el fin de lograr la integración densa de los componentes de unión de paso fino es esencial. Aunque unión paso fino ha sido demostrado por algunas de las técnicas estándar, pero hay un vacío en términos de combinar juntos las otras características importantes tales como la flexibilidad, la rentabilidad, la velocidad, la precisión y la baja temperatura de procesamiento. Con el fin de cumplir con estos requisitos demostramos método de unión LIFT-asistida termo-compresión para la unión de paso fino de los componentes de OE. En LIFT, una película delgada de material a ser impreso (denominado el donante) se deposita sobre una cara de un sustrato de soporte transparente al láser (referido como el portador). La Figura 1 representa el principio básico de esta técnica. Un pulso de láser incidente de suficiente intensidad se centra entonces en la interfaz carrier-donante que proporciona la fuerza propulsora necesaria para reenviar transferir el pixel de donantes de la zona irradiada sobre otro sustrato (referido como el receptor) situado en las proximidades. LIFT se informó por primera vez en 1986 por Bohandy como una técnica para imprimir las líneas de cobre de tamaño micrométrico para la reparación de daños foto-máscaras 3. Desde su primera demostración de esta técnica ha ganado un interés significativo como una tecnología de fabricación de micro-nano para el patrón controlado y la impresión de una amplia gama de materiales tales como la cerámica, 4 CNTs 5, 6 puntos cuánticos, las células vivas 7, gráficoeno 8, para diversas aplicaciones tales como biosensores 9, OLEDs 10, componentes optoelectrónicos 11, sensores plasmónicas 12, orgánico-electrónica 13 y la unión 14,15 flip-chip. LIFT ofrece varias ventajas sobre los golpes y técnicas de unión flip-chip existentes, como la simplicidad, velocidad, flexibilidad, rentabilidad, alta resolución y precisión para el envasado de flip-chip de componentes de equipo original.

<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) de envasado es una tecnología clave para la realización de alto rendimiento, circuitos de ultra miniaturizado y de alta densidad en la industria microelectrónica. En esta técnica el chip y / o el sustrato es golpeado y los dos están unidos a través de estos topes conductores. Muchas de las técnicas que chocan se han desarrollado e intensamente investigado desde la introducción de la tecnología FC en 1960 1, tales como la impresión de la plantilla, golpes espárrago, la evaporación y electrolítico / galvanoplastia 2. A pesar del progreso que estos métodos han hecho todos ellos sufren de una o más de uno inconvenientes que deben abordarse tales como el costo, las etapas de procesamiento complejas, las temperaturas altas de procesamiento, el tiempo de fabricación y lo más importante la falta de flexibilidad. En este trabajo se demuestra una protuberancia técnica simple y rentable basado en láser que forma conocida como inducida por láser Transferencia Forward (LIFT) 3. Utilizando la técnica LIFT una amplia gama de materiales bump puede be impreso en un solo paso con gran flexibilidad, alta velocidad y precisión a TA. Además, LIFT permite al chocar y unión a chip de escala, lo cual es fundamental para la fabricación de circuitos de ultra-miniatura.

La Figura 7 muestra una curva típica LIV que fue grabado de uno de los muchos flip-chip unidos chips de VCSEL. Una buena combinación entre la potencia óptica medida al proveedor citó valores indicados buen funcionamiento de los dispositivos enlazados post-unión. Las curvas también se registraron prioridad y después de la encapsulación y en la comparación se verificó que el encapsulante no tuvo ningún efecto sobre la funcionalidad de chip (como se muestra en la Figura 7). Tamb...

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

Se demuestra el uso de la transferencia (LIFT) técnica Forward inducida por láser para el montaje flip-chip de componentes optoelectrónicos. Este enfoque proporciona una, rentable y de baja temperatura simple, solución rápida y flexible para chocar de paso fino y unión en el chip escala para alcanzar circuitos de alta densidad para aplicaciones optoelectrónicas.

Transferencia Forward inducida por láser para Flip-chip de embalaje de muñones individuales

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

Research

JoVE Journal

Engineering

12.2K vistas.  Ghent University-imec.  Se demuestra el uso de la transferencia (LIFT) técnica Forward inducida por láser para el montaje flip-chip de componentes optoelectrónicos. Este enfoque proporciona una, rentable y de baja temperatura simple, solución rápida y flexible para chocar de paso fino y unión en el chip escala para alcanzar circuitos de alta densidad para aplicaciones optoelectrónicas. 

Video: 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 Puntos Cuánticos for Imaging sola molécula

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

Investigación

Ingeniería

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.

Análisis de Contacto Interfaces para individuales GaN nanocables Dispositivos

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.

Medición y Análisis de hidrógeno atómico y molecular diatómico AlO, C<sub&gt; 2</sub&gt;, CN, y el TiO Spectra siguiente desglose óptica inducida por láser

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.

Inducida por láser Breakdown Spectroscopy: un nuevo enfoque para el mapeo y cuantificación de nanopartículas en tejidos de órganos

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.

De silicio metal-óxido-semiconductor Quantum Dots para Bombeo solo electrón

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.

Integración de luz de captura de plata de nanoestructuras en células solares de silicio hidrogenado microcristalina por transferencia Impresión

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.

Transferencia Forward inducida por láser de Ag nanopasta

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.

La fabricación de 1-D de cristal fotónico cavidad en un nanofibras Uso de ablación inducida por láser de femtosegundo

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.

Metodología basada en el perfilador de dispersión de luz de barrido (SLPS) para evaluar cuantitativamente la dispersión de luz hacia delante y hacia atrás desde lentes intraoculares

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.

Totalmente electrónico resuelto nanosegundo túnel microscopía: Facilitar la investigación de Dopant solo carga dinámica

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