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

1. LIFT-assistita flip-chip Bonding NOTA: Ci sono tre fasi coinvolte nella realizzazione assemblee flip-chip di LIFT-assistita, vale a dire-micro-urto dei substrati con la tecnica LIFT, allegando i chip optoelettronici ai substrati urtato con termo-compressione flip-chip di metodo di collegamento, e infine incapsulamento delle assemblee incollati. Ognuna di queste fasi è discusso nelle seguenti sezioni: <ol><li> Micro-urto con LIFT: <ol><li> Per la preparazione del donatore, depositare un film sottile di materiale donatore su un substrato portante laser-trasparente. Per questo esperimento, evaporare a 200 nm film spesso di metallo indio sopra vetro substrato di supporto con dimensioni: spessore del diametro x 0,05 centimetri 2 pollici. NOTA: metodo di preparazione del donatore dipende dalla fase del materiale donatore, ad esempio, utilizzare evaporazione e sputtering per materiali donatori fase solida e spin-coating e medico-palettatura per donatore fase liquidas. </li><li> Per la preparazione del ricevitore, utilizzare substrati di vetro con dimensioni di 5 x 5 x 0,07 centimetri 3 come ricevitori. Motivo questi substrati con le pastiglie di contatto metallici per l&#39;incollaggio il chip OE e fan-out di sondaggio strutture usando fotolitografia. Per questo esperimento, spessi rilievi obbligazionari Ni-Au pattern 4 micron e fan-out sondare piste su substrati di vetro del ricevitore. </li><li> Quindi, posizionare il donatore in contatto con il ricevitore e montare il gruppo donatore-ricevente su una fase di traduzione XY controllata dal computer. NOTA: A seconda della fase del materiale donatore (per esempio, solidi (indio) o liquido (inchiostro / incollare)) e il suo spessore, il donatore e substrati ricevitore sono posti a una separazione ottimale che può essere facilmente controllato (per esempio, mediante utilizzando distanziatori metallici). </li><li> Mettere a fuoco il fascio laser incidente all&#39;interfaccia carrier-donatore impiegando un obiettivo da 160 mm di lunghezza focale e la scansione del fascio (20 micron dimensione dello spot) in tutto il substrat donatoree per il trasferimento dei donatori micro-urti sul ricevitore obbligazionari-pad. Utilizzare una sorgente laser al picosecondo di 355 nm di lunghezza d&#39;onda e 12 durata dell&#39;impulso psec a LIFT urti indio sul ricevitore obbligazioni pad alla fluenza di 270 mJ / cm 2. NOTA: Le proprietà laser come l&#39;energia, no. di impulsi, l&#39;altezza della lente dell&#39;obiettivo, coordinate della posizione esatta sul substrato ricevente per la stampa donatori micro-urti e il pattern desiderato da trasferire sono accuratamente controllata da un programma per computer. Parametri sperimentali chiave (ad esempio, il trasferimento di fluenza) devono essere ottimizzati in caso di utilizzo di un&#39;altra sorgente laser. </li><li> Per urti spessi spostare il donatore a un luogo fresco e ripetere passo 1.1.4 più volte. Ad esempio, ripetere il punto 1.1.4 a sei volte per ottenere una pila di 6 dossi indio stampate su uno sopra l&#39;altro per questo esperimento. La finale sollevò dossi hanno un&#39;altezza media di circa 1,5 micron e un diametro di 20 micron (Figura 2). NOTA: Per questi speriments il profilo della superficie e lo spessore degli urti sono stati misurati utilizzando un profilometro ottico. E &#39;stato verificato che le asperità avevano una morfologia convesso / cupola con uno spessore medio di 1,5 micron, una media di oltre il diametro urto (come indicato giallo in figura 3). La ragione di questo è attribuita al fatto che il donatore fuso nella zona laser irradiato e il pellet trasferito poi ri-solidificato raggiungimento superficie del ricevitore (Indium ha un basso punto di fusione). Il vantaggio di questo è che risulta in buona adesione della urto stampata alle piazzole di contatto VCSEL. </li></ol></li><li> Chip al supporto adesivo termo-compressione (Figure 4-6): <ol><li> Utilizzare una semiautomatica flip-chip di bonder per incollare i chip optoelettronici ai substrati urtato. </li><li> Caricare il ricevitore urtato e il chip da incollare sui rispettivi piatti vuoto del bonder. Posizionare il chip in posizione capovolta, cioè, con la sua area attiva facmento. </li><li> Utilizzare un utensile prelevatore adatto e allinearlo al centro del chip. Utilizzare un utensile a forma di ago, come mostrato in Figura 5. Successivamente, scegliere il chip utilizzando questo strumento di accompagnamento. </li><li> Allineare i chip di obbligazioni pad con le pastiglie di contatto corrispondenti sul substrato ricevitore utilizzando un sistema di telecamere di allineamento. </li><li> Una volta allineato posto il chip sul substrato. </li><li> Applicare calore (~ 200 ° C) e pressione (12,5 gf / urto) simultaneamente per realizzare chip substrato interconnessioni elettriche e meccaniche. </li></ol></li><li> Incapsulamento delle assemblee incollati (Figure 4-6): <ol><li> Erogare un adesivo otticamente trasparente attorno ai bordi del complesso legato utilizzando un ago della siringa. L&#39;incapsulamento aumenta l&#39;affidabilità meccanica degli assemblaggi incollati. Utilizzare un singolo componente UV adesivo curabile come NOA 86 per incapsulare i chip legati. </li><li> Curare l&#39;adesivo con una lampada UV per ~ 30 sec. </li></ol></li></ol> 2. Caratterizzazione dei Bonded verticale-cavità superficie di uscita laser (VCSEL) NOTA: Dopo la fabbricazione il prossimo passo è quello di valutare la performance elettro-ottico delle assemblee incollati. Il light-corrente-tensione (LIV) curve dei dispositivi sono registrati post-bonding utilizzando una stazione di sonda. Le seguenti operazioni sono coinvolti per la sperimentazione: <ol><li> Posizionare il flip-chip legato dispositivo su un palco trasparente su misura. Lo stadio ha un foro nel centro per un facile accesso alla luce emessa dai VCSEL. </li><li> Inserire un fotorivelatore (PD) sotto la fase trasparente e allineare la sua area attiva con il chip incollato utilizzando un microscopio. </li><li> Proprio posizionare gli aghi di sondaggio sul Ni-Au sonda pad utilizzando un microscopio. </li><li> Iniettare fino a 10 mA di corrente e misurare la caduta di tensione attraverso il VCSEL e la luce emessa da utilizzando una corrente / tensione unità sorgente metri e un misuratore di potenza resture rispettivamente. </li></ol>

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The authors have nothing to disclose.

In questo lavoro, abbiamo dimostrato termocompressione Flip-chip bonding di chip VCSEL singoli utilizzando una tecnica di scrittura diretta basata sul laser chiamato LIFT. Le fasi di fabbricazione assemblaggio coinvolte stampa dei micro-urti di indio sulle piazzole di contatto del substrato con la tecnica ascensore. Questo è stato seguito da termocompressione Flip-chip bonding di chip VCSEL ai substrati urtato e infine la loro incapsulamento. Elettrica, ottica e meccanica affidabilità dei ...

Laser-indotta Transfer Forward (LIFT) è un metodo di produzione versatile-scrittura diretta additivo per la definizione del modello single-step e il trasferimento di materiale con micron e sub-micron-risoluzione. In questo lavoro, si segnala l&#39;uso di LIFT come tecnica sbattere per il confezionamento flip-chip verticale-cavità superficie di uscita laser (VCSEL) su un chip-scala. Flip-chip è una tecnologia chiave nella confezione sistema ed integrazione di (OE) componenti elettronici ed optoelettronici. Per raggiungere densa integrazione di componenti fini incollaggio pitch è essenziale. Anche se passo fine legame è stato dimostrato da alcune delle tecniche standard, ma c&#39;è un vuoto in termini di combinare insieme le altre caratteristiche importanti come la flessibilità, economicità, velocità, precisione e bassa temperatura di lavorazione. Per soddisfare queste esigenze abbiamo dimostrato il metodo di incollaggio LIFT-assistita termo-compressione per passo fine incollaggio di componenti OE. In LIFT, una sottile pellicola di materiale da stampare (denominato donatore) viene depositata su una faccia di un substrato di supporto laser trasparente (denominato carrier). La Figura 1 illustra il principio di base di questa tecnica. Un impulso laser incidente di intensità sufficiente viene poi concentrata all&#39;interfaccia carrier-donatore che fornisce la forza propulsiva necessaria per trasmettere trasferire il pixel donatore dalla zona irradiata su un altro substrato (denominato ricevitore) posto in prossimità. LIFT è stata segnalata per la prima nel 1986 da Bohandy come tecnica per stampare linee in rame micron di dimensioni per la riparazione di danni foto-maschera 3. Dalla sua prima dimostrazione questa tecnica ha raggiunto livelli significativi come tecnologia di fabbricazione di micro-nano per patterning controllata e la stampa di una vasta gamma di materiali come la ceramica 4, 5, CNT QD 6, 7 cellule viventi, il graficoene 8, per le diverse applicazioni, quali biosensori 9, OLED 10, componenti optoelettronici 11, sensori plasmoniche 12, organico-elettronica 13 e legame 14,15 flip-chip. LIFT offre diversi vantaggi rispetto le flip-chip di urti e incollaggio tecniche esistenti, quali la semplicità, velocità, flessibilità, economicità, ad alta risoluzione e precisione per il confezionamento flip-chip componenti 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) imballaggio è una tecnologia chiave per realizzare elevate prestazioni, circuiti ultra-miniaturizzato e alta densità nell&#39;industria microelettronica. In questa tecnica il chip e / o il substrato è urtato ei due sono legati tramite questi urti conduttivi. Molte tecniche bumping sono state sviluppate e intensamente indagato dopo l&#39;introduzione della tecnologia FC nel 1960 1 come la stampa stencil, stallone urto, l&#39;evaporazione e electroless / galvanica 2. Nonostante i progressi che questi metodi hanno tutti soffrono di uno o più di inconvenienti che devono essere affrontati come costo, fasi di elaborazione complesse, alte temperature di lavorazione, il tempo di fabbricazione e soprattutto la mancanza di flessibilità. In questo lavoro, dimostriamo un laser-based urto tecnica di formatura semplice e conveniente nota come Laser indotta Transfer Forward (LIFT) 3. Utilizzando la tecnica LIFT una vasta gamma di materiali urto può be stampato in un unico passaggio, con grande flessibilità, ad alta velocità e la precisione a RT. Inoltre, LIFT permette di urtare e legame verso il basso per chip-scale, che è fondamentale per la realizzazione di un circuito ultra-miniatura.

La figura 7 mostra una curva tipica LIV che è stato registrato da uno dei tanti flip-chip di circuiti integrati VCSEL incollati. Una buona corrispondenza tra la potenza ottica misurata al fornitore citato valori indicati buon funzionamento del periferiche associate post-bonding. Le curve sono state registrate anche prior- e post-incapsulamento e sul confronto è stato verificato che l&#39;incapsulante non ha avuto effetto sulla funzionalità del circuito integrato (come mostrato nella Figura 7)...

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

Dimostriamo l&#39;uso della Forward Transfer (LIFT) tecnica laser-indotta per l&#39;assemblaggio flip-chip componenti optoelettronici. Questo approccio fornisce un conveniente, a bassa temperatura semplice, soluzione veloce e flessibile per la messa a passo urti e incollaggio sul chip-scala per raggiungere i circuiti ad alta densità per applicazioni optoelettroniche.

Laser-indotta Transfer Forward per Flip-chip Packaging di Dies Singolo

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

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12.2K Views.  Ghent University-imec.  Dimostriamo l'uso della Forward Transfer (LIFT) tecnica laser-indotta per l'assemblaggio flip-chip componenti optoelettronici. Questo approccio fornisce un conveniente, a bassa temperatura semplice, soluzione veloce e flessibile per la messa a passo urti e incollaggio sul chip-scala per raggiungere i circuiti ad alta densità per applicazioni optoelettroniche. 

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 Quantum Dots per singola molecola Imaging

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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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.

Analisi di contatto Interfacce semplici dispositivi GaN nanowire

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.

Misura e Analisi di idrogeno atomico e molecolare Diatomic AlO, C<sub&gt; 2</sub&gt;, CN, e TiO Spectra Following Laser-Induced Breakdown ottico

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.

Spettroscopia Laser-Induced Breakdown: un nuovo approccio per la mappatura di nanoparticelle e la quantificazione in Tissue Organ

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.

Silicio metallico-ossido-semiconduttore Quantum Dots per singolo elettrone di pompaggio

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.

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 ...

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.

Indotta da laser trasferimento di andata di 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 ...

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.

Fabbricazione di 1-D Photonic cristallo cavità su una nanofibre Utilizzando ablazione laser a femtosecondi-indotta

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.

Metodologia basata sulla scansione della luce di scansione (SLPS) per valutare quantitativamente la diffusione della luce avanti e indietro dalle lenti intraoculari

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.

Tutto-elettronico nanosecondo-risolto scansione microscopio a effetto tunnel: Agevolare le indagini di drogante singola carica dinamica

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