1. Preparazione del supporto <ol><li> Tagliare 1 cm x 1 centimetri substrati di silicio di un wafer di silicio, il silicio è un bene per la caratterizzazione SEM (vista in pianta e sezione). </li><li> Tagliare 1 cm x 1 cm vetro (soda-calce, 1 mm di spessore), il vetro è ottimale per la caratterizzazione ottica ed elettrica. </li><li> Se i contatti sono necessari su substrati di vetro, contatti Au può essere evaporato sotto vuoto utilizzando una maschera. Cauzione 10 nm di Cr come intercalare per migliorare l&#39;adesione di Au, deposito 50 nm di Au. </li><li> Tagliare 1 cm x 1 cm campione di polimero (ad esempio etilene tetrafluoroetilene, ETFE). </li><li> Pulire i substrati sonicating in isopropanolo per 5-10 minuti e risciacquare in isopropanolo, asciugare con un flusso di N 2. </li></ol> 2. Laser di allineamento e selezione dei parametri laser <ol><li> Warm-up del laser Nd: YAG e selezionare IV emissione armonica (266 nm) utilizzando un generatore di quarta armonica (FHG) costituito da due segeneratori cond armoniche (SHG) in cascata. </li><li> Montare un peso del 2%. Al 2 O 3:. ZnO bersaglio circolare (&quot;diametro 2) sul manipolatore destinazione Allineare il punto laser al centro del bersaglio, inizia la rotazione target e traduzione e impostare l&#39;intervallo verticale massimo Verificare che mai il punto laser tocca l&#39;esterno. Anello acciaio utilizzato per fissare il bersaglio. Il bersaglio viene spostato con un movimento roto-traslatorio avere ablazione uniforme della superficie target. </li><li> Selezionare la frequenza di ripetizione (ad esempio 10 Hz) e impulso di energia (ad esempio, 75 mJ). Regolare impulso di energia e stabilità laser monitor un misuratore di potenza. </li><li> Spostare la lente di focalizzazione ad una posizione selezionata e utilizzare un pezzo di carta sensibile collegata al bersaglio per misurare la dimensione del punto. Per qualunque posizione delle lente di focalizzazione fuoco colpi laser 1-5 sulla carta. Selezionare una posizione dell&#39;obiettivo per avere una fluenza laser di circa 1 J / cm 2. </li></ol> 3. Impostazione di un PLDd Selezione dei parametri di deposizione <ol><li> Allineamento della posizione substrato <ol><li> Montare un foglio circolare di carta di circa 2 &quot;di diametro come substrato per test di allineamento. </li><li> Spostare il supporto substrato ad un bersaglio a distanza d substrato TS = 50 mm. </li><li> Avviare il pompaggio del camera con pompe primarie e turbomolecolare fino a quando il livello di vuoto raggiunge 10 -2 Pa. </li><li> Selezionare un tipo di gas (ovvero, ossigeno) e regolare la velocità di pompaggio e di flusso di gas per avere la giusta pressione del gas (vedere sezioni 4 e 5). Regolare la posizione xy del manipolatore substrato fuori asse rispetto al centro pennacchio di ottenere film di spessore uniforme su una corona circolare. </li><li> Inizia ablazione rimuovendo il tappo / misuratore di potenza del fascio. Se il bersaglio è nuovo o se non è stato utilizzato per lungo tempo, questo pre-ablazione è necessario pulire il bersaglio. </li><li> Interrompere ablazione quando un deposito può essere visto sul paper guardando da una finestra. </li></ol></li><li> Determinazione della lunghezza pennacchio plasma <ol><li> Seguire i punti 3.1.1. a 3.1.5, durante l&#39;ablazione scattare foto con una fotocamera digitale con 0,5 - 1 volta accumulo sec per media diversi pennacchi di plasma. </li><li> Misurare la lunghezza visibile pennacchio plasma dalle fotografare d TS come riferimento (vedi Figura 3). </li></ol></li><li> Calibrazione dello spessore del film <ol><li> Spostare il supporto lontano dal bersaglio (cioè 100 mm e più) e spostare il quarzo Micro-Balance (QCM) ad una distanza pari a d TS dal bersaglio. </li><li> Deposito 1000 scatti laser (vale a dire 1 &#39;40&#39;&#39;) e misurare il valore della massa depositata, quindi spostare il QCM via. </li><li> Montare un substrato di Si come in 1.1. </li><li> Depositare un campione di prova (ad esempio, 18.000 colpi di laser, vale a dire 30 &#39;) e di utilizzare immagini di sezioni trasversali SEM per calibrate la velocità di deposizione (nm / impulso). </li></ol></li></ol> 4. Deposizione di nanoengineered AZO Films <ol><li> Montare i supporti preparati come al punto 1 sul manipolatore supporto campione con del nastro adesivo. </li><li> Seguire i punti 3.1.2 - 3.1.3. </li><li> Avviare la rotazione del substrato. </li><li> Deposizione di film di AZO compatti <ol><li> Accendere il cannone ionico e ioni energia impostata a 100 eV, potenza RF a 75-100 W e flusso di gas Ar a 20 sccm (la pressione è nel campo di 10 -2 Pa). Substrati puliti con Ar + cannone ionico per 5-10 min. Dopo la pulizia ingresso del gas di trattamento di gas e liquidi stretta la camera per rimuovere Argon. </li><li> Inserire ossigeno e regolare la velocità di pompaggio e il flusso di gas di avere 2 Pa ossigeno. </li><li> avviare ablazione e deposito per 18.000 colpi (30 &#39;). Durante controllo ablazione che la lunghezza pennacchio è la stessa come determinato nel passo 3,2. </li><li> smettere di ablazione, vicino gcome ingresso, la camera di pump down. </li></ol></li><li> Deposizione di film strutturati gerarchicamente AZO <ol><li> Inserire gas ossigeno e regolare la velocità di pompaggio e di flusso di gas per avere 160 Pa ossigeno. </li><li> avviare ablazione e deposito per 18.000 colpi (30 &#39;). Durante controllo ablazione che la lunghezza pennacchio è la stessa come determinato nel passo 3,2. </li><li> smettere di ablazione, vicino ingresso del gas, pump down la camera. </li></ol></li><li> Sfiatare la camera e prelevare campioni </li></ol> 5. Caratterizzazione elettrica ed ottica <ol><li> Misurare le proprietà nel piano di trasporto con quattro sonde tecniche (ad esempio il metodo Van der Pauw). Vedere Figura 4 per uno schema dei contatti. Valori tipici della corrente sonda sono in μA 1-10 mA. Le misurazioni viene eseguita su un&#39;area campione ridotto a 0,7 cm x 0,7 centimetri per garantire una uniformità di spessore maggiore (circa il 5%). </li><li> Misurare la optical trasmittanza del campione e del substrato nudo. Correggere gli spettri per il contributo substrato Impostare a 1 per l&#39;intensità con il vetro / film interfaccia. Per la procedura di correzione precisa assicurarsi che il campione è montato con il substrato di vetro di fronte al fascio incidente. Determinare la trasparenza della luce visibile calcolando la trasmittanza media nell&#39;intervallo 400-700 nm. Utilizzare una sfera di diametro 150 mm integrazione per misurare la frazione diffusa della luce, il fattore Haze può essere calcolato dividendo la frazione dispersa dalla luce totale trasmessa (cioè disperse e in avanti trasmessa), vedi figura 5. </li></ol>

<ol>
	<li>Chrisey, D. B., Hubler, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Pulsed Laser Deposition of Thin Films. , (1994).</li><li>Lowndes, D. H., Geohegan, D. B., Puretzky, A. A., Norton, D. P., Rouleau, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+novel+thin-film+materials+by+pulsed+laser+deposition.">Synthesis of novel thin-film materials by pulsed laser deposition.</a> Science. 273, 898 (1996).</li><li>Di Fonzo, F., Bailini, A., Russo, V., Baserga, A., Cattaneo, D., Beghi, M. G., Ossi, P. M., Casari, C. S., Li Bassi, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+characterization+of+nanostructured+tungsten+and+tungsten+oxide+films.">Synthesis and characterization of nanostructured tungsten and tungsten oxide films.</a> Catalysis Today. 116, 69-73 (2006).</li><li>Casari, C. S., Foglio, S., Passoni, M., Siviero, F., Bottani, C. E., Li Bassi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Energetic+regimes+and+growth+mechanisms+of+pulsed+laser+deposited+Pd+clusters+on+Au(111)+investigated+by+in+situ+Scanning+Tunneling+Microscopy.">Energetic regimes and growth mechanisms of pulsed laser deposited Pd clusters on Au(111) investigated by in situ Scanning Tunneling Microscopy.</a> Physical Review B. 84 (111), 155441 (2011).</li><li>Cattaneo, D., Foglio, S., Casari, C. S., Li Bassi, A., Passoni, M., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Different+W+cluster+deposition+regimes+in+pulsed+laser+ablation+observed+by+in+situ+Scanning+Tunneling+Microscopy.">Different W cluster deposition regimes in pulsed laser ablation observed by in situ Scanning Tunneling Microscopy.</a> Surface Science. 601, 1892-1897 (2007).</li><li>Bailini, A., Di Fonzo, F., Fusi, M., Casari, C. S., Li Bassi, A., Russo, V., Baserga, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+laser+deposition+of+tungsten+and+tungsten+oxide+thin+films+with+tailored+structure+at+the+nano-+and+mesoscale.">Pulsed laser deposition of tungsten and tungsten oxide thin films with tailored structure at the nano- and mesoscale.</a> Applied Surface Science. 253, 8130-8135 (2007).</li><li>Fusi, M., Russo, V., Casari, C. S., Li Bassi, A., A, C. E., Bottani, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Titanium+oxide+nanostructured+films+by+reactive+pulsed+laser+deposition.">Titanium oxide nanostructured films by reactive pulsed laser deposition.</a> Applied Surface Science. 255 (10), 5334-5337 (2009).</li><li>Dellasega, D., Facibeni, A., Fonzo, F. D. i., Russo, V., Conti, C., Ducati, C., Casari, C. S., Li Bassi, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanostructured+High+Valence+Silver+Oxide+Produced+by+Pulsed+laser+Deposition.">Nanostructured High Valence Silver Oxide Produced by Pulsed laser Deposition.</a> Applied Surface Science. 255 (10), 5248-5251 (2009).</li><li>Di Fonzo, F., Tonini, D., Li Bassi, A., Casari, C. S., Beghi, M. G., Bottani, C. E., Gastaldi, D., Vena, P., Contro, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+regimes+in+pulsed+laser+deposition+of+alumina+films.">Growth regimes in pulsed laser deposition of alumina films.</a> Applied Physics A. 93, 765-769 (2008).</li><li>Bailini, A., Donati, F., Zamboni, M., Russo, V., Passoni, M., Casari, C. S., Li Bassi, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+Laser+Deposition+of+Bi2Te3+Thermoelectric+Films.">Pulsed Laser Deposition of Bi2Te3 Thermoelectric Films.</a> Applied Surface Science. 254, 1249-1254 (2007).</li><li>Baserga, A., Russo, V., Fonzo, F. D. i., Bailini, A., Cattaneo, D., Casari, C. S., Li Bassi, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanostructured+Tungsten+Oxide+With+Controlled+Properties:+Synthesis+And+Raman+Characterization.">Nanostructured Tungsten Oxide With Controlled Properties: Synthesis And Raman Characterization.</a> Thin Solid Films. 515, 6465-6469 (2007).</li><li>Dellasega, D., Facibeni, A., Di Fonzo, F., Bogana, M., Polissi, A., Conti, C., Ducati, C., Casari, C. S., Li Bassi, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanostructured+Ag4O4+films+with+enhanced+antibacterial+activity.">Nanostructured Ag4O4 films with enhanced antibacterial activity.</a> Nanotechnology. 19, 475602 (2008).</li><li>Fonzo, F. D. i., Casari, C. S., Russo, V., Brunella, M. F., Li Bassi, A., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hierarchically+organized+nanostructured+TiO2+for+photocatalysis+applications.">Hierarchically organized nanostructured TiO2 for photocatalysis applications.</a> Nanotechnology. 20, 015604 (2009).</li><li>Torta, F., Fusi, M., Casari, C. S., Bottani, C. E., Bachi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Titanium+Dioxide+Coated+MALDI+plate+for+on+target+Analysis+of+Phosphopeptides.">Titanium Dioxide Coated MALDI plate for on target Analysis of Phosphopeptides.</a> Journal of Proteome Research. 8, 1932-1942 (2009).</li><li>Ponzoni, A., Russo, V., Bailini, A., Casari, C. S., Ferroni, M., Li Bassi, A., Migliori, A., Morandi, V., Ortolani, L., Sberveglieri, G., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Structural And Gas-Sensing Characterization Of Tungsten Oxide Nanorods And Nanoparticles. Sensors &amp; Actuators: B. Chemical B. 153, 340-346 (2011).</li><li>Li Bassi, A., Bailini, A., Donati, F., Russo, V., Passoni, M., Mantegazza, A., Casari, C. S., Bottani, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermoelectric+properties+of+Bi-Te+Films+with+controlled+structure+and+morphology.">Thermoelectric properties of Bi-Te Films with controlled structure and morphology.</a> Journal of Applied Physics. 105, 124307 (2009).</li><li>Sauvage, F., Di Fonzo, F., Li Bassi, A., Casari, C. S., Russo, V., Divitini, G., Ducati, C., Bottani, C. E., Comte, P., Graetzel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bio-inspired+hierarchical+TiO2+photo-anode+for+dye-sensitized+solar+cells.">Bio-inspired hierarchical TiO2 photo-anode for dye-sensitized solar cells.</a> Nano Letters. 10, 2562-2567 (2010).</li><li>Grankvist, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transparent+conductors+as+solar+energy+materials:+A+panoramic+review.">Transparent conductors as solar energy materials: A panoramic review.</a> Solar Energy Materials &amp; Solar Cells. 91, 1529 (2007).</li><li>Minami, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transparent+conducting+oxide+semiconductors+for+transparent+electrodes.">Transparent conducting oxide semiconductors for transparent electrodes.</a> Semicond. Sci. Technol. 20, S35 (2005).</li><li>Fortunato, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transparent+Conducting+Oxides+for+Photovoltaics.">Transparent Conducting Oxides for Photovoltaics.</a> MRS Bulletin. 32, 242 (2007).</li><li>Exarhos, G. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovery-based+design+of+transparent+conducting+oxide+films.">Discovery-based design of transparent conducting oxide films.</a> Thin Solid Films. 515, 7025 (2007).</li><li>Gondoni, P., Ghidelli, M., Fonzo, F. D. i., Russo, V., Bruno, P., Mart-Rujas, J., Bottani, C. E., Li Bassi, A., Casari, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+functional+properties+of+Al:ZnO+thin+films+grown+by+Pulsed+Laser+Deposition+at+room+temperature.">Structural and functional properties of Al:ZnO thin films grown by Pulsed Laser Deposition at room temperature.</a> Thin Solid Films. 520, 4707-4711 (2012).</li><li>Gondoni, P., Ghidelli, M., Fonzo, F. D. i., Carminati, M., Russo, V., Li Bassi, A., Casari, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure-dependent+optical+and+electrical+transport+properties+of+nanostructured+Al-doped+ZnO.">Structure-dependent optical and electrical transport properties of nanostructured Al-doped ZnO.</a> Nanotechnology. 23, 365706 (2012).</li><li>Casari, C. S., Li Bassi, A., Arkin, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+Laser+Deposition+of+Nanostructured+Oxides:+from+Clusters+to+Functional+Films.">Pulsed Laser Deposition of Nanostructured Oxides: from Clusters to Functional Films.</a> Advances in Laser and Optics Research. 7, 65-100 (2012).</li><li>Amoruso, S., Sambri, A., Vitiello, M., Wang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plume+expansion+dynamics+during+laser+ablation+of+manganates+in+oxygen+atmosphere.">Plume expansion dynamics during laser ablation of manganates in oxygen atmosphere.</a> Applied Surface Science. 252, 4712-4716 (2006).</li><li>Uccello, A., Dellasega, D., Perissinotto, S., Lecis, N., Passoni, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanostructured+Rhodium+Films+for+Advanced+Mirrors+Produced+by+Pulsed+Laser+Deposition.">Nanostructured Rhodium Films for Advanced Mirrors Produced by Pulsed Laser Deposition.</a> Journal of Nuclear Materials. , (2013).</li><li>Gondoni, P., Ghidelli, M., Fonzo, F. D. i., Russo, V., Bruno, P., Mart&#237;-Rujas, J., Bottani, C. E., Li Bassi, A., Casari, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+Performing+Al:ZnO+Thin+Films+grown+by+Pulsed+Laser+Deposition+at+Room+Temperature.">Highly Performing Al:ZnO Thin Films grown by Pulsed Laser Deposition at Room Temperature.</a> Nanoscience and Nanotechnology. , (2013).</li></ol>

Nessun conflitto di interessi dichiarati.

La forma pennacchio plasma è strettamente legato al processo di ablazione, soprattutto in presenza di un gas, il monitoraggio del pennacchio plasma mediante ispezione visiva è importante controllare la deposizione. Nel depositare un ossido metallico da ablare un target di ossido, l&#39;ossigeno è necessario per supportare le perdite di ossigeno durante il processo di ablazione. A bassa pressione gas di fondo di ossigeno, il materiale depositato può avere vacanze di ossigeno. Questo effetto è ridotto aumentando la p...

Deposizione laser pulsata (PLD) impiega ablazione laser di un bersaglio solido che risulta nella formazione di un plasma di specie ablata che può essere depositato su un substrato di crescita di un film (vedi Figura 1) 1. Interazione con una atmosfera di fondo (inerte o reattivo) può essere usato per indurre nucleazione omogenea cluster in fase gas (vedi figura 2) 2,3. La strategia per la sintesi di materiali da PLD si basa sulla regolazione delle proprietà materiali in un approccio ascendente un controllo accurato della dinamica plasma generato nel processo PLD. Dimensione dei cluster, energia cinetica e la composizione può essere variata da una corretta impostazione di parametri di deposizione che influenzano la crescita di film e comportano variazioni morfologiche e strutturali 4,5. Sfruttando il metodo descritto qui dimostrato, per una serie di ossidi (ad es WO 3, Ag 4 O 4, Al 2 O 3 and TiO 2), la capacità di regolare morfologia, densità, porosità, grado di ordine strutturale, stechiometria e fase modificando la struttura del materiale su scala nanometrica 6-11. Questo permette la progettazione di materiali per applicazioni specifiche 12-16. Con riferimento alle applicazioni fotovoltaiche, abbiamo sintetizzato TiO2 nanostrutturato gerarchicamente organizzato da nanoparticelle di montaggio (&lt;10 nm) in un nano-e mesostruttura che assomiglia a un &#39;foresta di alberi&#39; 13 mostra risultati interessanti quando impiegato come fotoanodi nelle tinture per celle solari sensibilizzate (DSSC ) 17. Sulla base di questi risultati precedenti si descrive il protocollo per la deposizione di Al-ZnO drogato (AZO) film come un ossido conduttore trasparente. Ossidi conduttori trasparenti (TCO) sono bandgap elevata (&gt; 3 eV) convertito in materiali conduttori dal drogaggio pesante, visualizzando resistività &lt;10 -3 ohm-cm e più del 80% ottica transmittance nel campo del visibile. Essi sono un elemento chiave per molte applicazioni come touch screen e celle solari 18-21 e sono tipicamente coltivate con tecniche differenti come sputtering, deposizione laser pulsata, deposizione chimica da vapore, pirolisi a spruzzo e con una soluzione a base di metodi chimici. Tra TCO, indio-stagno-ossido (ITO) è stato ampiamente studiato per la sua bassa resistività, ma presenta l&#39;inconveniente del costo elevato e bassa disponibilità di indio. La ricerca sta ora muovendo verso indio senza sistemi come F-drogato SnO 2 (FTO), Al-ZnO drogato (AZO) e F-ZnO drogato (FZO). Elettrodi in grado di fornire una gestione intelligente della luce incidente (intrappolamento luce) sono particolarmente interessanti per applicazioni fotovoltaiche. Per sfruttare la possibilità di disperdere la luce visibile attraverso strutture e morfologie modulati su scala paragonabili alla lunghezza d&#39;onda della luce (per esempio 300-1,000 nm), un buon controllo sulmorfologia film e sulle architetture di montaggio del cluster è necessario. In particolare, si descrive come ottimizzare la morfologia e la struttura dei film AZO. Compatta AZO depositato a bassa pressione (2 ossigeno Pa) a temperatura ambiente e caratterizzata da una bassa resistività (4,5 x 10 -4 ohm cm) e trasparenza alla luce visibile (&gt; 90%) che è competitiva con AZO depositati a temperature elevate, mentre AZO strutture gerarchiche sono ottenuti ablazione a O 2 pressioni superiori a 100 Pa. Tali strutture visualizzare una forte capacità diffondente con fattore di foschia fino al 80% e più 22,23.

<table border="1"><tbody><tr><td> Nome del reagente / materiale </td><td> Azienda </td><td> Numero di catalogo </td></tr><tr><td> Laser pulsato </td><td> Continuum-Quantronix </td><td> Powerlite 8010 </td></tr><tr><td> Potenza metro </td><td> Coerente </td><td> FieldMaxII-TO </td></tr><tr><td> Ion Gun </td><td> Mantis Dep </td><td> RFMax60 </td></tr><tr><td> Controllore di flusso di massa </td><td> Mks </td><td> 2179 ° </td></tr><tr><td> Di cristallo al quarzo Microbalance </td><td> Infcon </td><td> XTC / 2 </td></tr><tr><td> Sfondo di gas </td><td> Rivoira-Praxair </td><td> 5,0 di ossigeno </td></tr><tr><td> Obiettivo </td><td> Kurt Lesker </td><td> (Realizzato su richiesta) </td></tr><tr><td> Isopropanolo </td><td> Sigma Aldrich </td><td> 190.764-2L </td></tr><tr><td> Fonte metro </td><td> Keithley </td><td> K2400 </td></tr><tr><td> Magnet Kit </td><td> Ecopia </td><td> 0.55T-Kit </td></tr><tr><td> Spettrofotometro </td><td> PerkinElmer </td><td> Lambda 1050 </td></tr></tbody></table>

fabrication of nano-engineered transparent conducting oxides by pulsed laser deposition

Pulsed Laser Deposition nanosecondo (PLD) in presenza di un gas di fondo permette la deposizione di ossidi metallici con sintonizzabile morfologia, struttura, densità e stechiometria da un adeguato controllo della dinamica plasma pennacchio di espansione. Tale versatilità può essere sfruttata per produrre film nanostrutturati da nanoporoso denso e compatto per caratterizzata da un gruppo gerarchico di dimensioni nano cluster. In particolare si descrive la metodologia dettagliata per fabbricare due tipi di Al-ZnO drogato (AZO) film come elettrodi trasparenti in dispositivi fotovoltaici: 1) a bassa pressione O 2, film compatti con conducibilità elettrica e vicino trasparenza ottica allo stato dell&#39;arte ossidi trasparenti conduttori (TCO) possono essere depositati a temperatura ambiente, per essere compatibile con i materiali sensibili al calore come i polimeri utilizzati nel fotovoltaico organico (OPV), 2) strutture di scattering di luce altamente gerarchica simile ad una foresta di nano-alberi sono prodottiuced a pressioni superiori. Tali strutture mostrano elevato fattore di Haze (&gt; 80%) e può essere sfruttata per aumentare la capacità di cattura della luce. Il metodo qui descritto per film AZO può essere applicato ad altri ossidi metallici pertinenti per applicazioni tecnologiche come TiO 2, Al 2 O 3, WO 3 e Ag 4 O 4.

La deposizione di AZO da PLD in atmosfera di ossigeno produce compatte film trasparenti conduttori a bassa pressione gas di fondo (cioè 2 Pa) e mesoporosi foresta-come le strutture costituite da gruppi gerarchicamente assemblati a pressioni elevate (160 Pa). Il materiale è costituito da domini nanocristallini cui dimensione è massima (30 nm) a 2 Pa 22. A causa di collisioni tra le specie ablato e il gas di sfondo, la forma e la lunghezza del pennacchio plasma ...

Watch this Scientific Journal Video about Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition at JoVE.com

Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Descriviamo il metodo sperimentale per depositare film sottili di ossidi nanostrutturati da Pulsed Laser Deposition nanosecondi (PLD) in presenza di un gas di fondo. Utilizzando questo metodo di Al-ZnO drogato (AZO) film, dalla compatta alla gerarchicamente strutturata come nano-alberi delle foreste, possono essere depositati.

Fabbricazione di nano-ingegneria trasparenti Ossidi Conducting da Pulsed Laser Deposition

Nanosecond Pulsed  Laser Deposition (PLD) in the presence of a background gas allows the deposition  of metal oxides with tunable morphology, structure, ...

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Engineering

15.4K Views.  Politecnico di Milano. Descriviamo il metodo sperimentale per depositare film sottili di ossidi nanostrutturati da Pulsed Laser Deposition nanosecondi (PLD) in presenza di un gas di fondo. Utilizzando questo metodo di Al-ZnO drogato (AZO) film, dalla compatta alla gerarchicamente strutturata come nano-alberi delle foreste, possono essere depositati.

Video: Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a significant role in laser-material interaction, especially in the air environment1-11.
Early plasma evolution has been captured through pump-probe shadowgraphy1-3 and interferometry1,4-7. However, the studied time frames and applied laser parameter ranges are limited. For example, direct examinations of plasma front locations and electron number densities within a delay time of 100 picosecond (ps) with respect to the laser pulse peak are still very few, especially for the ultrashort pulse of a duration around 100 femtosecond (fs) and a low power density around 1014 W/cm2. Early plasma generated under these conditions has only been captured recently with high temporal and spatial resolutions12. The detailed setup strategy and procedures of this high precision measurement will be illustrated in this paper. The rationale of the measurement is optical pump-probe shadowgraphy: one ultrashort laser pulse is split to a pump pulse and a probe pulse, while the delay time between them can be adjusted by changing their beam path lengths. The pump pulse ablates the target and generates the early plasma, and the probe pulse propagates through the plasma region and detects the non-uniformity of electron number density. In addition, animations are generated using the calculated results from the simulation model of Ref. 12 to illustrate the plasma formation and evolution with a very high resolution (0.04 ~ 1 ps).
Both the experimental method and the simulation method can be applied to a broad range of time frames and laser parameters. These methods can be used to examine the early plasma generated not only from metals, but also from semiconductors and insulators.

An experimental method to examine the early plasma evolution induced by ultrashort laser pulses is described. Using this method, high quality images of early plasma are obtained with high temporal and spatial resolutions. A novel integrated atomistic model is used to simulate and explain the mechanisms of early plasma.

Indagine su Evolution Plasma precoce indotta da impulsi laser ultracorti

Early plasma is generated owing to high intensity laser irradiation of target and the subsequent target material ionization. Its dynamics plays a ...

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Ingegneria

Fabrication of Spatially Confined Complex Oxides

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from the inherent strong electron correlations that reside within them. These materials can also possess electronic phase separation in which regions of vastly different resistive and magnetic behavior can coexist within a single crystal alloy material. By reducing the scale of these materials to length scales at and below the inherent size of the electronic domains, novel behaviors can be exposed. Because of this and the fact that spin-charge-lattice-orbital order parameters each involve correlation lengths, spatially reducing these materials for transport measurements is a critical step in understanding the fundamental physics that drives complex behaviors. These materials also offer great potential to become the next generation of electronic devices 1-3. Thus, the fabrication of low dimensional nano- or micro-structures is extremely important to achieve new functionality. This involves multiple controllable processes from high quality thin film growth to accurate electronic property characterization. Here, we present fabrication protocols of high quality microstructures for complex oxide manganite devices. Detailed descriptions and required equipment of thin film growth, photo-lithography, and wire-bonding are presented.

We describe the use of pulsed laser deposition (PLD), photolithography and wire-bonding techniques to create micrometer scale complex oxides devices. The PLD is utilized to grow epitaxial thin films. Photolithography and wire-bonding techniques are introduced to create practical devices for measurement purposes.

Fabbricazione di ossidi complessi spazialmente confinati

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from ...

Making Record-efficiency SnS Solar Cells by Thermal Evaporation and Atomic Layer Deposition

Tin sulfide (SnS) is a candidate absorber material for Earth-abundant, non-toxic solar cells. SnS offers easy phase control and rapid growth by congruent thermal evaporation, and it absorbs visible light strongly. However, for a long time the record power conversion efficiency of SnS solar cells remained below 2%. Recently we demonstrated new certified record efficiencies of 4.36% using SnS deposited by atomic layer deposition, and 3.88% using thermal evaporation. Here the fabrication procedure for these record solar cells is described, and the statistical distribution of the fabrication process is reported. The standard deviation of efficiency measured on a single substrate is typically over 0.5%. All steps including substrate selection and cleaning, Mo sputtering for the rear contact (cathode), SnS deposition, annealing, surface passivation, Zn(O,S) buffer layer selection and deposition, transparent conductor (anode) deposition, and metallization are described. On each substrate we fabricate 11 individual devices, each with active area 0.25 cm2. Further, a system for high throughput measurements of current-voltage curves under simulated solar light, and external quantum efficiency measurement with variable light bias is described. With this system we are able to measure full data sets on all 11 devices in an automated manner and in minimal time. These results illustrate the value of studying large sample sets, rather than focusing narrowly on the highest performing devices. Large data sets help us to distinguish and remedy individual loss mechanisms affecting our devices.

Tin sulfide (SnS) is a candidate material for Earth-abundant, non-toxic solar cells. Here, we demonstrate the fabrication procedure of the SnS solar cells employing atomic layer deposition, which yields 4.36% certified power conversion efficiency, and thermal evaporation which yields 3.88%.

Rendere record efficienza SnS celle solari per evaporazione termica e Atomic Layer Deposition

Tin sulfide (SnS) is a candidate absorber material for Earth-abundant, non-toxic solar cells. SnS offers easy phase control and rapid growth by congruent ...

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75&#176;. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm2, respectively, has decreased the CA to near 15&#176;, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer&#8217;s surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of&#160;the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103&#176;. The XPS results indicate ArF laser induced formation of Si&#8211;(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with&#160;H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.

Area selettiva Modifica della Silicon bagnabilità della superficie da impulsi laser UV irradiazione in ambiente liquido

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication 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 ...

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, &#960;-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (&#181;-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, &#181;-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.

Fabbricazione di microsfere di polimeri per risonatore ottico e applicazioni laser

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, ...

Scalable Solution-processed Fabrication Strategy for High-performance, Flexible, Transparent Electrodes with Embedded Metal Mesh

Here, the authors report the embedded metal-mesh transparent electrode (EMTE), a new transparent electrode (TE) with a metal mesh completely embedded in a polymer film. This paper also presents a low-cost, vacuum-free fabrication method for this novel TE; the approach combines lithography, electroplating, and imprint transfer (LEIT) processing. The embedded nature of the EMTEs offers many advantages, such as high surface smoothness, which is essential for organic electronic device production; superior mechanical stability during bending; favorable resistance to chemicals and moisture; and strong adhesion with plastic film. LEIT fabrication features an electroplating process for vacuum-free metal deposition and is favorable for industrial mass production. Furthermore, LEIT allows for the fabrication of metal mesh with a high aspect ratio (i.e., thickness to linewidth), significantly enhancing its electrical conductance without adversely losing optical transmittance. We demonstrate several prototypes of flexible EMTEs, with sheet resistances lower than 1 &#937;/sq and transmittances greater than 90%, resulting in very high figures of merit (FoM) &#8211; up to 1.5 x 104 &#8211; which are amongst the best values in the published literature.

This protocol describes a solution-based fabrication strategy for high-performance, flexible, transparent electrodes with fully-embedded, thick metal mesh. Flexible transparent electrodes fabricated by this process demonstrate among the highest reported performances, including ultra-low sheet resistance, high optical transmittance, mechanical stability under bending, strong substrate adhesion, surface smoothness, and environmental stability.

Strategia di Fabbricazione elaborata in soluzione scalabile per elettrodi ad alte prestazioni, flessibili e trasparenti con maglia metallica incorporata

Here, the authors report the embedded metal-mesh transparent electrode (EMTE), a new transparent electrode (TE) with a metal mesh completely embedded in a ...

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.&#160; Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

We present a detailed method for fabricating ultra-thin color films with improved characteristics for optical coatings. The oblique angle deposition technique using an electron beam evaporator allows improved color tunability and purity. Fabricated films of Ge and Au on Si substrates were analyzed by reflectance measurements and color information conversion.

Fabbricazione di film ultra-sottile di colore con altamente assorbente Media mediante deposizione di angolo obliquo

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present ...

Production of Single Tracks of Ti-6Al-4V by Directed Energy Deposition to Determine the Layer Thickness for Multilayer Deposition

Directed Energy Deposition (DED), which is an additive manufacturing technique, involves the creation of a molten pool with a laser beam where metal powder is injected as particles. In general, this technique is employed to either fabricate or repair different components. In this technique, the final characteristics are affected by many factors. Indeed, one of the main tasks in building components by DED is the optimization of process parameters (such as laser power, laser speed, focus, etc.) which is usually carried out through an extensive experimental investigation. However, this sort of experiment is extremely lengthy and costly. Thus, in order to accelerate the optimization process, an investigation was conducted to develop a method based on the melt pool characterizations. In fact, in these experiments, single tracks of Ti-6Al-4V were deposited by a DED process with multiple combinations of laser power and laser speed. Surface morphology and dimensions of single tracks were analyzed, and geometrical characteristics of melt pools were evaluated after polishing and etching the cross-sections. Helpful information regarding the selection of optimal process parameters can be achieved by examining the melt pool features. These experiments are being extended to characterize the larger blocks with multiple layers. Indeed, this manuscript describes how it would be possible to quickly determine the layer thickness for the massive deposition, and avoid over or under-deposition according to the calculated energy density of the optimum parameters. Apart from the over or under-deposition, time and materials saving are the other great advantages of this approach in which the deposition of multilayer components can be started without any parameter optimization in terms of layer thickness.

In this research, a rapid method based on melt pool characterization is developed to estimate the layer thickness of Ti-6Al-4V components produced by directed energy deposition.

Produzione di singole tracce di Ti-6Al-4V per deposizione di energia diretta per determinare lo spessore di strato per deposizione multistrato

Directed Energy Deposition (DED), which is an additive manufacturing technique, involves the creation of a molten pool with a laser beam where metal ...

Generation and Coherent Control of Pulsed Quantum Frequency Combs

We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional states on-chip in a practical way have remained elusive due to the increasing complexity of the quantum circuitry needed to prepare and process such states. Here, we outline how high-dimensional, frequency-bin entangled, two-photon states can be generated at a stable, high generation rate by using a nested-cavity, actively mode-locked excitation of a nonlinear micro-cavity. This technique is used to produce pulsed quantum frequency combs. Moreover, we present how the quantum states can be coherently manipulated using standard telecommunications components such as programmable filters and electro-optic modulators. In particular, we show in detail how to accomplish state characterization measurements such as density matrix reconstruction, coincidence detection, and single photon spectrum determination. The presented methods form an accessible, reconfigurable, and scalable foundation for complex high-dimensional state preparation and manipulation protocols in the frequency domain.

A protocol is presented for the practical generation and coherent manipulation of high-dimensional frequency-bin entangled photon states using integrated micro-cavities and standard telecommunications components, respectively.

Generazione e controllo coerente di pettini di frequenza pulsata Quantum

We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional ...