Diese Forschung wird mit Unterstützung der Engineering and Physical Sciences Research Council (EPSRC) gefördert durch ein Doktorandenausbildung Zuschuss dankbar vorgenommen. Open Access-Artikel Bearbeitungsgebühren (APCs) wurden von Research Councils UK (RCUK) gefördert. Alle Daten werden im Ergebnisteil des Papiers in vollem Umfang zur Verfügung gestellt. Repräsentative Ergebnisse wurden bereits von den Autoren 42 veröffentlicht. Wir möchten bei der Charakterisierung der elektrischen Leistung der Zellen Dr. Senthilarasu Sundaram von der University of Exeter für seine Hilfe danken.

1. Tintenformulierung Hinweis: Tintenformulierungen sind oft ein sehr vorsichtiges Geheimnis von den Herstellern gehalten. Erfolgreiche Formulierungen Gleichgewicht Strahlen, Tropfenbildung, Benetzung und Trocknungsverhalten neben funktionalen Leistung. Üblicherweise eine funktionelle Material in einem Lösungsmittel dispergiert sind, und mindestens eine weitere Komponente, um sie strahlbaren machen. Dieser Abschnitt erläutert die Entwicklung einer Tinte TiO 2 zur Verwendung im Tintenstrahldruck. Eine kleine Charge von Druckfarbe wurde durch das folgende Verfahren hergestellt. Achtung: Die Farbe der Zubereitung sollte in einem geeignet belüfteten Bereich, zum Beispiel unter einem Abzug durchgeführt werden, während Auge trägt eine Schutzbrille und Latex - Handschuhe. <ol><li> Bereiten einer 0,1 mM wässrigen Lösung von Salzsäure (HCl) mit einem pH-Wert von etwa 4 zu erzeugen. </li><li> Hinzufügen von 32 g der sauren Lösung auf 8 g eines kompatiblen Lösungsmittels mit einem höheren Siedepunkt und niedriger Oberflächenspannung als Wasser (wie Dimethylformamid (DMF)). Die Zugabe eines Co-solvent dient als Trocknungsmittel eine Zirkulationsströmung innerhalb des Tintentröpfchens , wenn die Tinte verdampft, was zu einer gleichförmigen Anordnung von Nanopartikeln auf der Oberfläche des Tropfens 21 zu induzieren. </li><li> Hinzufügen 1,5 g Dispergieradditiv (45% aktive Lösung aus Propylenglykol und Tetramethyl-5-decin-4,7-diol in Wasser). </li><li> 10 g Ethylenglykol, als Feuchthaltemittel Trocknen an den Düsen zu verhindern. </li><li> Mit 0,5 g Entschäumungsmittel (20% aktive Lösung von acetylenischen Diols in Methoxypolyethylenglycol) zu der Tinte Luftblasen zu verhindern, zu entwickeln. </li><li> Führen Sie eine einfache Shake-Test durch einen aliquoten Teil der Tinte in einen geschlossenen Behälter zu nehmen und schütteln mit der Hand für 60 Sekunden. Wenn irgendein Schaum beobachtet wird dann fügen Sie eine weitere 0,5 g Mittel auf die Tinte von Entschäumer. </li><li> Mischen Sie die Lösung für 8 h einen magnetischen Rührstab mit Homogenität bei RT zu gewährleisten. </li><li> Hinzufügen , 1,5 g Titandioxid (TiO 2) Nanoteilchen mit einer primären Teilchengrße von 21 nm und einer Oberfläche von35 - 65 m 2 / g. </li><li> Beschallen der Mischung bei einer Frequenz von 60 Hz eine Ultraschallsonde für 15 Minuten verwendet wird. </li><li> Messung der Partikelgrößen, eine geeignete Messtechnik, wie beispielsweise dynamische Lichtstreuung (DLS) unter Verwendung von nach dem Protokoll des Herstellers, um sicherzustellen, dass sie leicht durch die Düsenöffnungen fließt. Stellen Messungen unter den gleichen Bedingungen (z. B. gleiche Lösungsmittel, pH, die Konzentration des Dispersionsmittels ) für die Tinte , wie jede Komponente verwendet werden , können die Bildung von Agglomeraten in der Tinte beeinflussen. Für eine erfolgreiche Strahlen, die Partikel innerhalb des Fluids sollte 100 mal kleiner als die Düsenöffnung sein. </li><li> Messen der Viskosität der Tinte, eine geeignete Messtechnik, wie einem Rotations-Viskosimeter nach Herstellerprotokoll verwendet, zuverlässige Ausstoßen aus dem Druckkopf zu gewährleisten, wie Tintenstrahldruck niedriger Viskosität Tinten zwischen 2 und 20 Centipoise (cP) erfordert. Erhöhen Sie die Viskosität durch die additiauf polymerer Materialien oder Materialien auf Cellulosebasis; jedoch müssen diese nach der Abscheidung entfernt werden , freizugeben Stellen für den Farbstoff in der gedruckten Films 22. </li><li> Messen der Oberflächenspannung der Tinte, eine geeignete Messtechnik, wie einem Tensiometer nach Herstellerprotokoll verwendet, zuverlässige Ausstoßen zu gewährleisten. Die Strahlbare Fluidformulierung Richtlinien für Tintenstrahldrucker deuten auf eine Oberflächenspannung zwischen 28 und 33 mN / m höchste Zuverlässigkeit beim Drucken zu ermöglichen. </li></ol> 2. Inkjet Printing <ol><li> Vor dem Drucken tränken die Glassubstrate in einer 2 Gew% ige Lösung des Waschmittels Reinigung (eine Mischung aus anionischen und nichtionischen oberflächenaktiven Mittel, Stabilisierungsmittel, Alkalien, nicht-Phosphat-Detergensbuilder und Sequestriermittel in einer wässrigen Base) in VE-Wasser. Spülen Sie das Glas gründlich mit entionisiertem Wasser, sobald sie aus der Reinigungslösung entfernt werden, Spuren von Verunreinigungen zu entfernen und Reinigungsmittel. </li&gt; <li> Messung der Oberflächenenergie des Substrats, eine geeignete Messtechnik, wie einem Tensiometer Verwendung nach dem Protokoll des Herstellers. Für eine gute Haftung sollte die Oberflächenenergie des Substrats nicht die Oberflächenspannung des Fluids überschreitet um mehr als 10 bis 15 mN / m. Modifizieren , um die Oberflächenenergie des Substrats Methoden wie Coronabehandlung 23, Plasmabehandlung 24 und chemisches Ätzen unter Verwendung von 25 , wenn er nicht geeignet ist. </li><li> Laden des Substrats in dem Drucker nach dem Protokoll des Herstellers. </li><li> Spülen Sie den Druckkopf mit der Tinte durch den Anschluss an der Seite des Kopfes keine Luft oder Reinigungslösung innerhalb des Reservoirs und Düsen zu verdrängen. </li><li> Setzen Sie den Druckkopf in den Drucker. Schließen Sie den Druckkopf mit dem Kopf Persönlichkeit Bord. </li><li> Filtern, um die Tinte durch die richtige Größe Filter nur vor dem Laden in die Kassette großer Partikelaggregate zu entfernen, die die Düsen verstopfen können. DasDruckkopf in dieser Arbeit verwendet hat Düsen mit einem Durchmesser von 40 &amp; mgr; m (zB Konica KM512.); daher Tinten sollten keine Teilchen enthalten mit einem Durchmesser über 400 nm. Führen Sie die Suspensionen durch ein 5 &amp; mgr; m, durch einen 1,2 um Polyvinylidenfluorid (PVDF) Filter gefolgt alle großen Partikel zu entfernen. </li><li> Laden Sie die Tinte in die 150-ml-Spritze über dem Druckkopf befindet, der die Tinte an den Druckkopf liefert. Bringen Sie den luftdichten Deckel auf der Oberseite der Spritze und schalten Sie die Vakuumpumpe. </li><li> Spülen Sie die Tinte durch die Düsen durch Drücken der &quot;Säuberung&quot; Taste auf der Vakuumpumpe. </li><li> die Wellenform und Druckparameter Durch die geographischen Informationssystems (GIS) Printserver, Set-up. Beachten Sie, dass der Drucker mit einer Geschwindigkeit von 1,5 Meter pro Sekunde drucken kann, jedoch für diese Tinte einer Druckgeschwindigkeit von 0,3 Meter pro Sekunde hat sich gezeigt, eine optimale Beschichtung bereitzustellen </li><li> Open GIS Benutzeroberfläche Software und laden Sie das gewünschte Muster. </li><li> Print aus der beladenen Kartusche nach dem Protokoll des Herstellers. </li><li> Entfernen des Substrats von der Platte und erwärmen die bedruckten Folien bei 150 ºC für 30 min, gefolgt von 250 ºC für weitere 30 min entweder auf einer Heizplatte oder in einem Ofen. </li></ol> 3. Analyse der bedruckten Folien <ol><li> Verwenden eines optischen Mikroskops oder eines Rasterelektronenmikroskops (SEM) auf der Oberfläche der bedruckten Folien zu sehen bei geringer Vergrößerung (100X), um die Oberflächenmorphologie und bei hoher Vergrößerung (35,000X) zu analysieren, um die Porosität der bedruckten Folien zu analysieren. Überprüfen Sie, ob die Bilder eine gleichmäßige Abdeckung ohne Risse und eine gute Porosität zeigen. Nähere Informationen über SEM Operation kann 26,27 in den folgenden Referenzen gefunden werden. </li><li> Die Dicke der gedruckten Schicht, eine geeignete Messtechnik, wie beispielsweise eine Oberfläche Profiler nach dem Protokoll des Herstellers. Die Dicke und Porosität der TiO 2 -Schicht witHin DSSCs beeinflussen die Menge an Farbstoff , die auf der Oberfläche der Nanoteilchen absorbiert werden kann, was somit die gesamte elektrische Umwandlungseffizienz der Zelle 18 beeinflussen. Es ist daher ein wichtiger Parameter, zu bewerten. Verwenden, um eine Oberflächenprofil (Genauigkeit von 1 nm), die Dicke der bedruckten Folien zu messen. </li><li> Messen der Durchlässigkeit des Films, eine geeignete Messverfahren wie beispielsweise ein ultraviolett-sichtbares (UV-VIS) Spektrophotometer verwendet, um zu bestimmen, wie viel sichtbares Licht durch die bedruckte Folie übertragen wird. Verwenden Protokoll des Herstellers. </li></ol> 4. Machen Sie die Zelle <ol><li> Bilden eine Farbstofflösung mit 20 ml Ethanol gemischt und 2 mg Ruthenium-Farbstoff in einem Becherglas einen Magnetrührer für 8 h verwendet wird. </li><li> Unterzutauchen die TiO 2 beschichtetem Glas in der Lösung bei RT (20 bis 25 ° C) für 24 h der Farbstoff zu ermöglichen , auf der Oberfläche der TiO 2 -Teilchen zu absorbieren. </li><li> Entfernen Sie die TiO 2 </sub&gt; beschichtetes Glas aus der Lösung und Stelle auf Tissue - Papier überschüssige Farbstofflösung aufzusaugen (mit TiO 2 nach oben zu vermeiden Kontamination hin). </li><li> Legen Sie die vorgeschnittenen 60 &amp; mgr; m dicken thermoplastischen Dichtungsabstandhalter auf der Oberseite des leitenden Glas, um die TiO 2 -Beschichtung. </li><li> Legen Sie die mit Platin beschichteten Gegenelektrode auf der Oberseite des vorgeschnittenen 60 &amp; mgr; m dicken thermoplastischen Dichtungsabstandhalter, so dass die aktiven Seiten der Anode und der Kathode sind einander zugewandt sind. Erlauben genug Überlappung zwischen den zwei Glasscheiben, so dass ein elektrischer Kontakt mit dem leitfähigen Glas hergestellt sein. Dies sollte ein vorgebohrtes Loch in der Mitte später für die Elektrolytfüllung zu ermöglichen haben. </li><li> Wärme auf einer Heizplatte auf eine Temperatur von 110 ° C und Druck ausüben Licht Pinzette über den Bereich des Dichtungsabstandshalter verwendet wird. Nach 30 sec sollten die Elektroden miteinander versiegelt werden. </li><li> Die Lücke zwischen den beiden Elektroden mit einer Jodid / Triiodid-electroLyte in Acetonitril bei einer Konzentration von 50 mM, indem in dem Platin beschichtetes Glas durch die vorgebohrten Löcher injizierende unter Verwendung einer Spritze. </li></ol>

<ol>
	<li>Docampo, P., 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=Lessons+Learned:+From+Dye-Sensitized+Solar+Cells+to+All-Solid-State+Hybrid+Devices.">Lessons Learned: From Dye-Sensitized Solar Cells to All-Solid-State Hybrid Devices.</a> Adv. Mater. 26, 4013-4030 (2014).</li><li>Hudd, A., Magdassi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Chemistry of Inkjet Inks. , 3-18 (2009).</li><li>Krebs, F. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+and+processing+of+polymer+solar+cells:+A+review+of+printing+and+coating.">Fabrication and processing of polymer solar cells: A review of printing and coating.</a> Sol. Energ. Mat. Sol. Cells. 93, 394-412 (2009).</li><li>Reddy, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Solar Power Generation: Technology, New Concepts &amp; Policy. , (2012).</li><li>Gemeiner, P., Mikula, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Acta. Chem. Slov. 6, 29 (2013).</li><li>Xue, Z., Jiang, C., Wang, L., Liu, W., Liu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Flexible+Plastic+Solid-State+Dye-Sensitized+Solar+Cells+Using+Low+Temperature+Techniques.">Fabrication of Flexible Plastic Solid-State Dye-Sensitized Solar Cells Using Low Temperature Techniques.</a> J. Phys. Chem. C. 118, 16352-16357 (2014).</li><li>Oh, Y., Yoon, H. G., Lee, S. -. N., Kim, H. -. K., Kim, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet-Printing+of+TiO2+Co-Solvent+Ink:+From+Uniform+Ink-Droplet+to+TiO2+Photoelectrode+for+Dye-Sensitized+Solar+Cells.">Inkjet-Printing of TiO2 Co-Solvent Ink: From Uniform Ink-Droplet to TiO2 Photoelectrode for Dye-Sensitized Solar Cells.</a> J. Electrochem. Soc. 159, 34-38 (2011).</li><li>Lin, L. -. Y., 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=Low-temperature+flexible+Ti/TiO2+photoanode+for+dye-sensitized+solar+cells+with+binder-free+TiO2+paste.">Low-temperature flexible Ti/TiO2 photoanode for dye-sensitized solar cells with binder-free TiO2 paste.</a> Prog. Photovolt. Res. Appl. 20, 181-190 (2012).</li><li>Gong, J., Liang, J., Sumathy, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review+on+dye-sensitized+solar+cells+(DSSCs):+Fundamental+concepts+and+novel+materials.">Review on dye-sensitized solar cells (DSSCs): Fundamental concepts and novel materials.</a> Renew. Sustainable Energy Rev. 16, 5848-5860 (2012).</li><li>Bosch-Jimenez, P., Yu, Y., Lira-Cantu, M., Domingo, C., Ayll&#242;n, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solution+processable+titanium+dioxide+precursor+and+nanoparticulated+ink:+Application+in+Dye+Sensitized+Solar+Cells.">Solution processable titanium dioxide precursor and nanoparticulated ink: Application in Dye Sensitized Solar Cells.</a> J Colloid Interf Sci. 416, 112-118 (2014).</li><li>Jose, R., Thavasi, V., Ramakrishna, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metal+Oxides+for+Dye-Sensitized+Solar+Cells.">Metal Oxides for Dye-Sensitized Solar Cells.</a> J. Am. Ceram. Soc. 92, 289-301 (2009).</li><li>Gemeiner, P., Mikula, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficiency+of+dye+sensitized+solar+cells+with+various+compositions+of+TiO2+based+screen+printed+photoactive+electrodes.">Efficiency of dye sensitized solar cells with various compositions of TiO2 based screen printed photoactive electrodes.</a> Acta. Chem. Slov. 6, 29-34 (2013).</li><li>Lee, K. E., Charbonneau, C., Demopoulos, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thin+single+screen-printed+bifunctional+titania+layer+photoanodes+for+high+performing+DSSCs+via+a+novel+hybrid+paste+formulation+and+process.">Thin single screen-printed bifunctional titania layer photoanodes for high performing DSSCs via a novel hybrid paste formulation and process.</a> J. Mater. Res. 28, 480-487 (2013).</li><li>Li, J., Lemme, M. C., &#246;stling, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet+Printing+of+2D+Layered+Materials.">Inkjet Printing of 2D Layered Materials.</a> ChemPhysChem. 15, 3427-3434 (2014).</li><li>Rudyak, V. Y., Krasnolutskii, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dependence+of+the+viscosity+of+nanofluids+on+nanoparticle+size+and+material.">Dependence of the viscosity of nanofluids on nanoparticle size and material.</a> Phys. Lett. A. 378, 1845-1849 (2014).</li><li>Dispoto, G., Moroney, N., Hanson, E., Meyer, J. D., Allen, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Color Desktop Printer Technology Optical Science and Engineering. , 111-155 (2006).</li><li>Hsien-Hsueh, L., Kan-Sen, C., Kuo-Cheng, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet+printing+of+nanosized+silver+colloids.">Inkjet printing of nanosized silver colloids.</a> Nanotechnology. 16, 2436 (2005).</li><li>Singh, M., Haverinen, H. M., Dhagat, P., Jabbour, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet+Printing:+Inkjet+Printing-Process+and+Its+Applications.">Inkjet Printing: Inkjet Printing-Process and Its Applications.</a> Adv. Mater. 22, 673-685 (2010).</li><li>St&#252;we, D., Mager, D., Biro, D., Korvink, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet+Technology+for+Crystalline+Silicon+Photovoltaics.">Inkjet Technology for Crystalline Silicon Photovoltaics.</a> Adv. Mater. 27, 599-626 (2015).</li><li>Perelaer, 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=Roll-to-Roll+Compatible+Sintering+of+Inkjet+Printed+Features+by+Photonic+and+Microwave+Exposure:+From+Non-Conductive+Ink+to+40%+Bulk+Silver+Conductivity+in+Less+Than+15+Seconds.">Roll-to-Roll Compatible Sintering of Inkjet Printed Features by Photonic and Microwave Exposure: From Non-Conductive Ink to 40% Bulk Silver Conductivity in Less Than 15 Seconds.</a> Adv. Mater. 24, 2620-2625 (2012).</li><li>Hwang, M. -. s., Jeong, B. -. y., Moon, J., Chun, S. -. K., Kim, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet-printing+of+indium+tin+oxide+(ITO)+films+for+transparent+conducting+electrodes.">Inkjet-printing of indium tin oxide (ITO) films for transparent conducting electrodes.</a> Mat. Sci. Eng. B. 176, 1128-1131 (2011).</li><li>Hara, K., Arakawa, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Photovoltaic Science and Engineering. , 663-700 (2003).</li><li>Ryu, J., Wakida, T., Takagishi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Corona+Discharge+on+the+Surface+of+Wool+and+Its+Application+to+Printing.">Effect of Corona Discharge on the Surface of Wool and Its Application to Printing.</a> Text. Res. J. 61, 595-601 (1991).</li><li>Yang, L., Chen, J., Guo, Y., Zhang, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+of+a+biomedical+polyethylene+terephthalate+(PET)+by+air+plasma.">Surface modification of a biomedical polyethylene terephthalate (PET) by air plasma.</a> Appl. Surf. Sci. 255, 4446-4451 (2009).</li><li>Qian, B., Shen, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Superhydrophobic+Surfaces+by+Dislocation-Selective+Chemical+Etching+on+Aluminum,+Copper,+and+Zinc+Substrates.">Fabrication of Superhydrophobic Surfaces by Dislocation-Selective Chemical Etching on Aluminum, Copper, and Zinc Substrates.</a> J. Am. Chem. Soc. 21, 9007-9009 (2005).</li><li>Echlin, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Sample Preparation for Scanning Electron Microscopy and X-Ray Microanalysis. , (2011).</li><li>Flegler, S. L., Heckman, J. W., Klomparens, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Scanning and Transmission Electron Microscopy: An Introduction. , (1993).</li><li>O'Donnell, M. Z. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+To+Minimize+Measurement+Errors+In+Solar+Cell+Testing.">How To Minimize Measurement Errors In Solar Cell Testing.</a> Solar Industry Magazine. , (2011).</li><li>Gr&#228;tzel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dye-sensitized+solar+cells.">Dye-sensitized solar cells.</a> J. Photochem. Photobiol. C: Photochem. Rev. 4, 145-153 (2003).</li><li>Green, M. A., Emery, K., Hishikawa, Y., Warta, W., Dunlop, E. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Solar+cell+efficiency+tables+(version+46).">Solar cell efficiency tables (version 46).</a> Prog. Photovolt. Res. Appl. 23, 805-812 (2015).</li><li>Shockley, W., Queisser, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detailed+Balance+Limit+of+Efficiency+of+p-n+Junction+Solar+Cells.">Detailed Balance Limit of Efficiency of p-n Junction Solar Cells.</a> J. Appl. Phys. 32, 510-519 (1961).</li><li>Snaith, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimating+the+Maximum+Attainable+Efficiency+in+Dye-Sensitized+Solar+Cells.">Estimating the Maximum Attainable Efficiency in Dye-Sensitized Solar Cells.</a> Adv. Funct. Mater. 20, 13-19 (2010).</li><li>Jeng, M. -. J., Wung, Y. -. L., Chang, L. -. B., Chow, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+Size+Effects+of+TiO2+Layers+on+the+Solar+Efficiency+of+Dye-Sensitized+Solar+Cells.">Particle Size Effects of TiO2 Layers on the Solar Efficiency of Dye-Sensitized Solar Cells.</a> Int. J. Photoenergy. 2013, 9 (2013).</li><li>Song-Yuan, D., Kong-Jia, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimum+Nanoporous+TiO2+Film+and+Its+Application+to+Dye-sensitized+Solar+Cells.">Optimum Nanoporous TiO2 Film and Its Application to Dye-sensitized Solar Cells.</a> Chin. Phys. Lett. 20, 953-955 (2002).</li><li>Baglio, V., Girolamo, M., Antonucci, V., Aric&#242;, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+TiO2+Film+Thickness+on+the+Electrochemical+Behaviour+of+Dye-Sensitized+Solar+Cells.">Influence of TiO2 Film Thickness on the Electrochemical Behaviour of Dye-Sensitized Solar Cells.</a> Int. J. Electrochem. Sci. 6, 3375-3384 (2011).</li><li>Ito, S., 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=High-Efficiency+Organic-Dye-+Sensitized+Solar+Cells+Controlled+by+Nanocrystalline-TiO2+Electrode+Thickness.">High-Efficiency Organic-Dye- Sensitized Solar Cells Controlled by Nanocrystalline-TiO2 Electrode Thickness.</a> Adv. Mater. 18, 1202-1205 (2006).</li><li>Ito, S., Kalyanasundaram, 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> Dye sensitized solar cells. , 251-266 (2010).</li><li>Tsai, J., Hsu, W., Wu, T., Meen, T., Chong, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+compressed+TiO2+nanoparticle+thin+film+thickness+on+the+performance+of+dye-sensitized+solar+cells.">Effect of compressed TiO2 nanoparticle thin film thickness on the performance of dye-sensitized solar cells.</a> Nanoscale Res Lett. 8, 1-6 (2013).</li><li>Shin, I., 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=Analysis+of+TiO2+thickness+effect+on+characteristic+of+a+dye-sensitized+solar+cell+by+using+electrochemical+impedance+spectroscopy.">Analysis of TiO2 thickness effect on characteristic of a dye-sensitized solar cell by using electrochemical impedance spectroscopy.</a> Curr. Appl. Phys. 10, 422-424 (2010).</li><li>Brus, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electronic+wave+functions+in+semiconductor+clusters:+experiment+and+theory.">Electronic wave functions in semiconductor clusters: experiment and theory.</a> J. Phys. Chem. 90, 2555-2560 (1986).</li><li>Jung, S., 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=All-Inkjet-Printed,+All-Air-Processed+Solar+Cells.">All-Inkjet-Printed, All-Air-Processed Solar Cells.</a> Adv Energy Mater. 4, 1-9 (2014).</li><li>Cherrington, R., Hughes, D. J., Senthilarasu, S., Goodship, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inkjet-Printed+TiO2+Nanoparticles+from+Aqueous+Solutions+for+Dye-Sensitized+Solar+Cells+(DSSCs).">Inkjet-Printed TiO2 Nanoparticles from Aqueous Solutions for Dye-Sensitized Solar Cells (DSSCs).</a> Energy Technology. 3, (2015).</li></ol>

Die Autoren haben nichts zu offenbaren.

A particular challenge when formulating inks is the natural tendency for nanoparticles to cluster together. These are known as either aggregates or agglomerates, depending on the nature and strength of the bonds between the particles. The energy of simply stirring particles into water or binder is not great enough to overcome the particle attractive forces preventing the breakup of agglomerates. Ball milling, high shear mixing or ultrasonication are commonly used to break up agglomerated nanoparticles. Various anionic, nonionic, and cationic surfactants and polymers can also be used to provide long-term stabilization. By minimizing the number of these agglomerates, a good quality suspension can be achieved. The fluids should be filtered through the correct size filter just before loading into the cartridge to remove large particle aggregates which can clog the nozzles.
The particle size within the TiO2 layer also has been shown to influence the overall efficiency of DSSCs. The photocatalytic activity of titanium dioxide increases as particle sizes decrease due to an increase in the specific surface area40. A study comparing the efficiency of DSSCs incorporating TiO2 nanoparticles with 5 different sizes ranging from 400 nm to 14 nm and found that those with smaller particle sizes resulted in better electrical conversion efficiencies33.
Inkjet printing is a non-contact deposition technique capable of multi-pass printing. This presents the unique opportunity to rapidly fabricate multilayer devices in one operation on a wide range of substrates with minimal material waste. It also potentially provides a way to integrate other components (such as batteries) into the system through the printing of functional materials41. Although the representative results shown for the inkjet printed devices do not perform as well as the doctor-bladed devices, it demonstrates the potential for the deposition technique. With further ink optimization, it could perform on a comparable level to currently used methods and may provide further scope for cost-effective, environmentally friendly integration of photovoltaic cells onto a wide range of substrates. We hope to improve the efficiency of the inkjet printed devices by increasing the thickness of the printed layer closer to that of the doctor-bladed TiO2 and will continue to look at the printing of other materials and layers within DSSCs.

Conventional silicon solar cells are made from highly pure materials that require expensive and high-energy consuming specialist equipment. These conventional silicon cells incorporate a p-n junction that requires highly pure materials at the interface to generate electron-hole pairs. Dye-sensitized solar cells (DSSCs) have a fundamentally different working principle, where charge generation takes place at the materials interface. This means that processing under vacuum, ultrahigh temperatures or the use of clean room facilities are not required1. Therefore they are seen as a potentially low cost alternative; however up-scaling from small laboratory test cells into large prototypes for industrial manufacturing involves overcoming several issues including the rapid patterning of substrates.
Electronics manufacturing generally requires a degree of patterning, which is either achieved by masking or selective removal of the material after deposition. These steps can be removed through the use of "additive" digital printing techniques such as inkjet printing or spray coating. Digital printing is a promising method for direct deposition of functional materials for electronic devices. The technique can be described as printing from a digital-based pattern directly to a variety of substrates2. They are non-contact methods, which will not damage or contaminate the substrate surface and deposit material only where it is required, resulting in little or no wastage3. These techniques have been highlighted as being ideally suited to being scaled up to high-volume production3. Since digital printing methods use liquid forms of materials dispersed in a solvent, it is critical to understand the deposition of ink to determine the applications of the technique. 
DSSCs have three main components: a porous layer of wide bandgap metal oxide material, a dye that covers the particles, and a "charge transporter" that infiltrates the pores within the porous layer of semiconductor. These are sandwiched in between a transparent conductive electrode and a counter electrode4. The counter electrode is coated with a catalytic material for electron transfer, which in most cases is platinum. Under illumination, the dye molecules will absorb energy in the form of photons. The dye molecules then become excited and charge separation occurs at the interface of the titanium dioxide and the dye. Electrons are ejected into the adjacent metal oxide particles and 'holes' are left behind on the dye molecule. The injected electrons travel through the metal oxide particles and reach the transparent conductive electrode. When a load is connected, the electrons move to the counter electrode through the external circuit and are finally reunited with their counter charges through the redox couple present in the electrolyte1. The nano-structured metal oxide layer within DSSCs plays a critical role in the overall performance of the cell, with material choice, processing methods and nature of the structure all having influencing factors5-10. One of the most important requirements for the photoanode is that it needs to have an extremely large surface area. This is achieved through the deposition of nanoparticle materials, commonly TiO21,11. This has been fabricated by countless different processes, however wet coating techniques such as screen-printing and doctor-blading, are still the most popular approach9,12,13. 
Inkjet technology is a potential manufacturing route for dye-sensitized solar cells. It uses the movement of a piezoelectric crystal to expel a fixed quantity of liquid through a nozzle onto the desired substrate. This deposition method allows material to be jetted very accurately but also at high frequency with a potentially high print speed or deposition rate. Inkjet technology is sensitive to the viscosity of the ink used and this was previously a barrier to the development of functional inks. Recent work in the development of solvents suitable for ink formulation has helped to alleviate this problem, and printing of electronic components using 2D layered materials such as graphene has been demonstrated14. The viscosity of nanoparticle suspensions such as these has been found to depend on the nanoparticle size and concentration15. High concentrations of nanoparticles result in higher viscosities, therefore particle loadings are usually around 10 wt% to avoid nozzle blockages16, however higher concentrations have been achieved17.
The key advantages of inkjet technology include it being non-contact, additive patterning and maskless18. The latter two attributes are due to the ability to position many nozzles together on one or more printheads, with each nozzle separately addressable by the control software. This allows highly complex, multi-layered patterns to be created very rapidly as the printheads move across the substrate. No masking between materials or layers is required as the position of each ink drop is accurately controlled, in some systems to an accuracy of ~1.5 &#181;m19. One of the key benefits is that inkjet technology is mature, with significant development carried out in the latter half of the twentieth century. The result is that the inkjet is a very scalable technology, with roll-to-roll systems capable of printing accurately onto flexible substrates at rates of many meters per second. Traditionally this was used for high volume production, e.g., newspapers. However, developments in technology have allowed the inkjet to be used in roll-to-roll production of electronic circuits using nanoparticulate silver inks20. The inkjet is therefore an attractive process for the potential production of dye-sensitized solar cells by digital printing.

<table>
	<tbody>
		<tr>
			<td>Titanium dioxide</td>
			<td>Sigma Aldrich</td>
			<td>718467</td>
			<td></td>
		</tr>
		<tr>
			<td>Deionized water&#160;</td>
			<td></td>
			<td></td>
			<td>Supplied from a filter in the laboratory</td>
		</tr>
		<tr>
			<td>Hydrochloric acid, 2M(2N)&#160;</td>
			<td>Fisher Scientific</td>
			<td>J/4250/17</td>
			<td></td>
		</tr>
		<tr>
			<td>Dimethylformamide (DMF)</td>
			<td>Fisher Scientific</td>
			<td>D/3840/08</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>VWR Chemicals</td>
			<td>20721.33</td>
			<td></td>
		</tr>
		<tr>
			<td>Dispersing additive&#160;</td>
			<td>Air Products</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Defoaming agent</td>
			<td>Air Products</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethylene glycol</td>
			<td>Fluka</td>
			<td>107-21-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyvinylidene fluoride (PVDF) syringe filter</td>
			<td>VWR International</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cleaning detergent&#160;</td>
			<td>Fisher Scientific</td>
			<td>10335650</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorine doped tin oxide (FTO) glass, 8 &#937;/sq</td>
			<td>Pilkington</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ruthenizer dye</td>
			<td>Solaronix</td>
			<td>21613</td>
			<td></td>
		</tr>
		<tr>
			<td>Pre-cut 60 &#181;m thick thermoplastic sealing film&#160;</td>
			<td>Solaronix</td>
			<td>74301</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mM iodide/tri-iodide electrolyte&#160; in acetonitrile</td>
			<td>Solaronix</td>
			<td>31111</td>
			<td></td>
		</tr>
		<tr>
			<td>Platinum coated FTO glass&#160;</td>
			<td>Solaronix</td>
			<td>74201</td>
			<td></td>
		</tr>
		<tr>
			<td>Vac&#39;n&#39;Fill Syringe</td>
			<td>Solaronix</td>
			<td>65209</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyimide tape (6.35 mm)</td>
			<td>Onecall Farnell</td>
			<td>1676087</td>
			<td></td>
		</tr>
	</tbody>
</table>

digital printing of titanium dioxide for dye sensitized solar cells

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less environmentally damaging with lower processing temperatures presenting a viable and low cost alternative to conventional production. This paper further enhances these environmental credentials by evaluating the digital printing and therefore additive production route for these cells. This is achieved here by investigating the formation and performance of a metal oxide photoelectrode using nanoparticle sized titanium dioxide. An ink-jettable material was formulated, characterized and printed with a piezoelectric inkjet head to produce a 2.6 &#181;m thick layer. The resultant printed layer was fabricated into a functioning cell with an active area of 0.25 cm2 and a power conversion efficiency of 3.5%. The binder-free formulation resulted in a reduced processing temperature of 250 &#176;C, compatible with flexible polyamide substrates which are stable up to temperatures of 350 &#730;C. The authors are continuing to develop this process route by investigating inkjet printing of other layers within dye sensitized solar cells.

Eine TiO 2 Tinte wurde nach dem dargestellten Verfahren formuliert. Die Größe der Partikel in der Tinte suspendiert wurde unter Verwendung von dynamischer Lichtstreuung (DLS) und eine mittlere Teilchengröße von 80 Nanometern (nm) gemessen wurde beobachtet. Die Viskosität der Tinte in dieser Arbeit gefunden wurde 3 cP zu sein, mit einem Rotationsviskosimeter mit einem kleinen Probenadapter gemessen und eine 18 mm Spindeldurchmesser. Die Oberflächenspannung wurde gemessen, um einen Tensiometer verwendet und berechnet einen Durchschnitt von 26 mN / m zu sein. Die Oberflächenenergie des FTO-Glas wurde nach der europäischen Norm EN 828 berechnet für die Benetzbarkeit einer festen Oberfläche zu bestimmen durch Messung des Kontaktwinkels und freie Energie Oberfläche. Zehn Tropfen von drei verschiedenen Flüssigkeiten (Wasser, Ethylenglykol und Diiodmethan) wurden auf einer Ebene Teststückoberfläche verteilt. Für jeden Tropfen, wurden die linken und rechten Kontaktwinkel measured. Aus den gemittelten Kontaktwinkel von jeder Flüssigkeit mit seiner Oberflächenspannung kombiniert wird, wird die freie Oberflächenenergie des Teststücks berechnet. Die Fowkes Methode berechnet die Gesamtoberflächenenergie (γ) aus der Summe der Beiträge von dispersiven Wechselwirkungen (&amp; ggr; d) und γnon dispersiven Wechselwirkungen (&amp; gamma; p). Diese Methode führte zu einer freien Oberflächenenergie von 26,45 mN / m für die FTO-beschichtetes Glas. Das Drucken wurde durchgeführt nach dem Verfahren von über 5 mm Quadrate herzustellen. Die Dicke der Druckschicht auf dem Glas wurde unter Verwendung eines Oberflächenprofil gemessen. Die maximale Dicke in der Mitte der Druckschicht wurde gemessen 2,6 um betrug. Die Durchlässigkeit des beschichteten Glases wurde unter Verwendung eines UV-VIS-Spektrometer gemessen. Bei einer Wellenlänge von 700 nm, eine 60% ​​ige Durchlässigkeit wurde für die TiO 2 bedruckter Folie , gemessen im Vergleich zu 78% für die Glas FTO. <p class="jove_content" fo:keep-together.within-page = &quot;1&quot;&gt; Photovoltaic Vorrichtungen wurden gemß dem Verfahren hergestellt outline oberhalb und unmittelbar nach der Herstellung dadurch die Wirkung der Abbau durch Wasser und Sauerstoff in der Luft verursacht werden, zu minimieren. Es gibt fünf elektrischen Leistungsparameter , die verwendet werden , um zu charakterisieren und zu Solarzellen 28 zu vergleichen. Die Werte der Kurzschlussstrom (I sc) und Leerlaufspannung (V oc) von der Strom-Spannungs (IV) Kurve ableiten. Diese können dann verwendet werden, um den Füllfaktor zu bestimmen (FF) und Leistungsumwandlungseffizienz (η). Das FF ergibt ein Verhältnis der Zellen tatsächliche maximale Leistungsabgabe an das Produkt der Leerlaufspannung und Kurzschlussstrom 29. Dies ist ein Schlüsselparameter in der Leistung von Solarzellen zu bewerten. Eine hohe FF bedeutet geringe elektrochemische Verluste, während eine niedrige FF gibt es Raum für Verbesserungen. Mehrere Faktoren sind dafür bekannt, die FF einschließlich der Qualität und der Schnittstelle der Schichten innerhalb der Zelle zu beeinflussen. DSSCs enthält ein Iodid / Triiodid Redoxpaar mit einem Rekordwirkungsgrade von 11,9% Bericht Faktoren von 0,71 30 füllen. Unter Standard - Testbedingungen müssen alle diese Parameter festgelegt werden , wo die Gerätetemperatur 25 ° C, spektrale Bestrahlungsstärke Verteilung des Lichts eine Luftmasse von 1,5 hat, Gesamtbestrahlungsstärke gemessen (E m) an der Solarzelle 100 mW / cm 2. Theoretische Maximum für den Umwandlungswirkungsgrad für einen einzelnen pn - Übergang Zelle wurde als 37,7% 31, jedoch für DSSCs berichtet wurde vielfach berichtet , daß der maximale Wirkungsgrad näher an 15,1% mit einem Absorptionsbeginn bei 920 nm 32. Der Ausgangsstrom und Spannungen wurden unter Verwendung einer Quelle Meter gemessen , während die Zellen mit einem 100 mW / cm 2 Lichtquelle mit einem Filter ausgestattet beleuchtet wurden mit einer Luftmasse von 1,5 die spektrale Bestrahlungsstärke Verteilung anzupassen. Die Ergebnisse wurden im Vergleich zu einer Zelleunter Verwendung eines Streichblatt-TiO 2 -Schicht mit einer handelsüblichen Paste hergestellt , die eine Mischung aus Anatas - Teilchen 20 nm und 450 nm aufweist. Die gedruckte Schicht hatte eine Fläche von 0,25 cm 2 und eine durchschnittliche Dicke von 18 um , die eine Oberfläche Profiler gemessen werden. Ein Vergleich der photoelektrischen Leistung zwischen den beiden Geräten wird in Abbildung 1 und Tabelle 1 gezeigt. Mehrere Studien haben die Beziehung zwischen der Dicke der TiO 2 -Schicht und der Umwandlungswirkungsgrad innerhalb DSSCs sucht. Die Ergebnisse unterscheiden sich erheblich, mit einer optimalen Schichtdicke von überall berichtet zwischen 9,5 um und 20 um 33-39. Tabelle 1 beschreibt die Dicke der TiO 2 gedruckten Schichten und die Wirkungsgrade. Die Dicke des TiO Tintenstrahldruck 2 ist deutlich geringer als der Arzt beschaufelten TiO 2, wasin einem geringeren Wirkungsgrad. Zukünftige Arbeiten werden die Verwendung von organischen Bindemittel in der Tintenformulierung zu untersuchen, die Dicke der Tintenstrahldruckschicht zu erhöhen. <img alt="Abbildung 1" src="/files/ftp_upload/53963/53963fig1.jpg" /> Abbildung 1. Leistungskurven von DSSCs mit Inkjet gedruckt und Doktor Bladed TiO 2 Schichten. Stromdichte / Spannungskurven für DSSCs eines Tintenstrahl enthält gedruckt TiO 2 -Schicht und einen Arzt Blatt-TiO2-Schicht. Der Kurzschlussstromdichte in dem Gerät mit dem Tintenstrahl - Druck TiO 2 -Schicht ist deutlich niedriger als das Gerät mit dem Arzt bladed TiO2-Schicht , was zu einer geringeren Gesamtwirkungsgrad. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53963/53963fig1large.jpg" target="_blank">Bitte hier klicken</a> , um <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53963/53963fig1large.jpg" target="_blank">eine größere Version dieser Figur zu sehen.</a> <table><tbody><tr><tdrowspan = &quot;3&quot;&gt; </td><td> Kurzschlussspannung </td><td> Leerlaufspannung </td><td rowspan="3"> Füllfaktor </td><td> Wirksamkeit </td><td> Dicke </td></tr><tr><td> (mA / cm 2) </td><td> (MV) </td><td></td><td></td></tr><tr><td></td><td></td><td> (%) </td><td> (Um) </td></tr><tr><td> Inkjet gedruckt </td><td> 9.42 </td><td> 760 </td><td> 0,49 </td><td> 3.5 </td><td> 2.6 </td></tr><tr><td> Doktor bladed </td><td> 11 </td><td> 756 </td><td> 0,58 </td><td> 4.8 </td><td> 18 </td></tr></tbody></table> Tabelle 1. Key Performance Eigenschaften der Zellen in Abbildung 1. Diese Tabelle vergleicht die wichtigsten Parameter der Solarzelle einschließlich Leerlaufspannung (V oc), Kurzschlussstrom (I sc) , die die Effizienz (η) unter dem angegebenen Licht bestimmen Zustand präsentiert. Die Parameter oproduziert fa Zelle einen Arzt Blatt-TiO2-Schicht auch zum Vergleich eingeschlossen wurden , verwenden. Die Füllfaktoren (FF) beider Geräte sind recht niedrig, die im Allgemeinen auf einen hohen Innenwiderstand innerhalb der Zelle zugeschrieben wird.

Watch this Scientific Journal Video about Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells at JoVE.com

Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells

This paper investigates the suitability of inkjet printing for the manufacturing of dye-sensitized solar cells. A binder-free TiO2 nanoparticle ink was formulated and printed onto a FTO glass substrate. The printed layer was fabricated into a cell with an active area of 0.25 cm2 and an efficiency of 3.5%.

Digitaldruck von Titandioxid für farbstoffsensibilisierte Solarzellen

Silicon solar cell manufacturing is an expensive and high energy consuming process. In contrast, dye sensitized solar cell production is less ...

digital-printing-of-titanium-dioxide-for-dye-sensitized-solar-cells

Nanyang Technological University

Research

JoVE Journal

Engineering

12.7K Aufrufe.  University of Warwick. This paper investigates the suitability of inkjet printing for the manufacturing of dye-sensitized solar cells. A binder-free TiO2 nanoparticle ink was formulated and printed onto a FTO glass substrate. The printed layer was fabricated into a cell with an active area of 0.25 cm2 and an efficiency of 3.5%.

Serie: Digital Printing of Titanium Dioxide for Dye Sensitized Solar Cells

Micro 3D Printing Using a Digital Projector and its Application in the Study of Soft Materials Mechanics

Buckling is a classical topic in mechanics. While buckling has long been studied as one of the major structural failure modes1, it has recently drawn new attention as a unique mechanism for pattern transformation. Nature is full of such examples where a wealth of exotic patterns are formed through mechanical instability2-5. Inspired by this elegant mechanism, many studies have demonstrated creation and transformation of patterns using soft materials such as elastomers and hydrogels6-11. Swelling gels are of particular interest because they can spontaneously trigger mechanical instability to create various patterns without the need of external force6-10. Recently, we have reported demonstration of full control over buckling pattern of micro-scaled tubular gels using projection micro-stereolithography (P&mu;SL), a three-dimensional (3D) manufacturing technology capable of rapidly converting computer generated 3D models into physical objects at high resolution12,13. Here we present a simple method to build up a simplified P&mu;SL system using a commercially available digital data projector to study swelling-induced buckling instability for controlled pattern transformation.
A simple desktop 3D printer is built using an off-the-shelf digital data projector and simple optical components such as a convex lens and a mirror14. Cross-sectional images extracted from a 3D solid model is projected on the photosensitive resin surface in sequence, polymerizing liquid resin into a desired 3D solid structure in a layer-by-layer fashion. Even with this simple configuration and easy process, arbitrary 3D objects can be readily fabricated with sub-100 &mu;m resolution.
This desktop 3D printer holds potential in the study of soft material mechanics by offering a great opportunity to explore various 3D geometries. We use this system to fabricate tubular shaped hydrogel structure with different dimensions. Fixed on the bottom to the substrate, the tubular gel develops inhomogeneous stress during swelling, which gives rise to buckling instability. Various wavy patterns appear along the circumference of the tube when the gel structures undergo buckling. Experiment shows that circumferential buckling of desired mode can be created in a controlled manner. Pattern transformation of three-dimensionally structured tubular gels has significant implication not only in mechanics and material science, but also in many other emerging fields such as tunable matamaterials.

We demonstrate controlled pattern transformation of swelling gel tubes by elastic instability. A simple projection micro stereo-lithography setup is built using an off-the-shelf digital data projector to fabricate three-dimensional polymeric structures in a layer-by-layer fashion. Swelling hydrogel tubes under mechanical constraint display various circumferential buckling modes depending on dimension.

Micro 3D-Druck mit einem digitalen Projektor und ihre Anwendung in der Studie von Soft Werkstoffmechanik

Buckling is a classical topic in mechanics. While buckling has long been studied as one of the major structural failure modes1, it has recently drawn new ...

Forschung

Ingenieurwesen

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date.

An integrated device, incorporating a dye-sensitized solar cell and triplet-triplet annihilation up-conversion unit was produced, affording enhanced light harvesting, from a wider section of the solar spectrum. Under modest irradiation levels a significantly enhanced response to low energy photons was demonstrated, yielding a record figure of merit for dye-sensitized solar cells.

Integration einer Triplett-Triplett-Annihilation Up-Conversion-System, um Farbstoffsolarzellantwort auf Sub-Bandgap-Licht Enhance

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents ...

Ambient Method for the Production of an Ionically Gated Carbon Nanotube Common Cathode in Tandem Organic Solar Cells

A method of fabricating organic photovoltaic (OPV) tandems that requires no vacuum processing is presented. These devices are comprised of two solution-processed polymeric cells connected in parallel by a transparent carbon nanotubes (CNT) interlayer. This structure includes improvements in fabrication techniques for tandem OPV devices. First the need for ambient-processed cathodes is considered. The CNT anode in the tandem device is tuned via ionic gating to become a common cathode. Ionic gating employs electric double layer charging to lower the work function of the CNT electrode. Secondly, the difficulty of sequentially stacking tandem layers by solution-processing is addressed. The devices are fabricated via solution and dry-lamination in ambient conditions with parallel processing steps. The method of fabricating the individual polymeric cells, the steps needed to laminate them together with a common CNT cathode, and then provide some representative results are described. These results demonstrate ionic gating of the CNT electrode to create a common cathode and addition of current and efficiency as a result of the lamination procedure.

A method of fabricating, in ambient conditions, organic photovoltaic tandem devices in a parallel configuration is presented. These devices feature an air-processed, semi-transparent, carbon nanotube common cathode.

Ambient Verfahren zur Herstellung eines ionisch Gated Carbon Nanotube Gemeinsame Kathode in Tandem Organische Solarzellen

A method of fabricating organic photovoltaic (OPV) tandems that requires no vacuum processing is presented. These devices are comprised of two ...

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.

Integration of Light Trapping Silber-Nanostrukturen in Hydrogenated Microcrystalline Silicon Solar Cells durch Transferdruck

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

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

Printing Herstellung von Bulk-Heterosolarzellen und<em&gt; In Situ</em&gt; Morphologie Charakterisierung

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells

Here, we demonstrate the incorporation of monovalent cation additives into CH3NH3PbI3 perovskite in order to adjust the optical, excitonic, and electrical properties. The possibility of doping was investigated by adding monovalent cation halides with similar ionic radii to Pb2+, including Cu+, Na+, and Ag+. A shift in the Fermi level and a remarkable decrease of sub-bandgap optical absorption, along with a lower energetic disorder in the perovskite, was achieved. An order-of-magnitude enhancement in the bulk hole mobility and a significant reduction of transport activation energy within an additive-based perovskite device was attained. The confluence of the aforementioned improved properties in the presence of these cations led to an enhancement in the photovoltaic parameters of the perovskite solar cell. An increase of 70 mV in open circuit voltage for AgI and a 2 mA/cm2 improvement in photocurrent density for NaI- and CuBr-based solar cells were achieved compared to the pristine device. Our work paves the way for further improvements in the optoelectronic quality of CH3NH3PbI3 perovskite and subsequent devices. It highlights a new avenue for investigations on the role of dopant impurities in crystallization and controls the electronic defect density in perovskite structures.

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells

Here, we present a protocol to adjust the properties of solution-processed CH3NH3PbI3 through the incorporation of monovalent cation additives in order to achieve highly efficient perovskite solar cells.

Einwertiges Kation Dotierung von CH<sub&gt; 3</sub&gt; NH<sub&gt; 3</sub&gt; PbI<sub&gt; 3</sub&gt; Für effiziente Perowskit-Solarzellen

Here, we demonstrate the incorporation of monovalent cation additives into CH3NH3PbI3 perovskite in order to adjust the optical, excitonic, and electrical ...

Electrospinning of Photocatalytic Electrodes for Dye-sensitized Solar Cells

This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of electrospun titanium dioxide nanofibers (TiO2-NFs) on top of a blocking layer made of commercially available titanium dioxide nanoparticles (TiO2-NPs). This is achieved by first electrospinning a solution of titanium (IV) butoxide, polyvinylpyrrolidone (PVP), and glacial acetic acid in ethanol to obtain composite PVP/TiO2 nanofibers. These are then calcined at 500 &#176;C to remove the PVP and to obtain pure anatase-phase titania nanofibers. This material is characterized using scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The photoanode is prepared by first creating a blocking layer through the deposition of a TiO2-NPs/terpineol slurry on a fluorine-doped tin oxide (FTO) glass slide using doctor blading techniques. A subsequent thermal treatment is performed at 500 &#176;C. Then, the light-scattering layer is formed by depositing a TiO2-NFs/terpineol slurry on the same slide, using the same technique, and calcinating again at 500 &#176;C. The performance of the photoanode is tested by fabricating a dye-sensitized solar cell and measuring its efficiency through J-V curves under a range of incident light densities, from 0.25-1 Sun.

The overall goal of this project was to use electrospinning to fabricate a photoanode with improved performance for dye-sensitized solar cells.

Elektrospinnen von photokatalytischen Elektroden für farbstoffsensibilisierte Solarzellen

This work demonstrates a protocol to fabricate a fiber-based photoanode for dye-sensitized solar cells, consisting of a light-scattering layer made of ...

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for Cu(In,Ga)Se2 Solar Cells

The levelized cost of electricity (LCOE) of photovoltaic (PV) systems is determined by, among other factors, the PV module reliability. Better prediction of degradation mechanisms and prevention of module field failure can consequently decrease investment risks as well as increase the electricity yield. An improved knowledge level can for these reasons significantly decrease the total costs of PV electricity. 
In order to better understand and minimize the degradation of PV modules, the occurring degradation mechanisms and conditions should be identified. This should preferably happen under combined stresses, since modules in the field are also simultaneously exposed to multiple stress factors. Therefore, two 'Combined Stress test with in situ measurement' setups have been designed and constructed. These setups allow the simultaneous use of humidity, temperature, illumination, and electrical biases as independently controlled stress factors on solar cells and minimodules. The setups also allow real-time monitoring of the electrical properties of these samples. This protocol presents these setups and describes the experimental possibilities. Moreover, results obtained with these setups are also presented: various examples about the influence of both deposition and degradation conditions on the stability of thin film Cu(In,Ga)Se2 (CIGS) as well as Cu2ZnSnSe4 (CZTS) solar cells are described. Results on the temperature dependency of CIGS solar cells are also presented.

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for CuIn,GaSe2 Solar Cells

Two &#39;Combined Stress test with in situ measurement&#39; setups, which allow real-time monitoring of accelerated degradation of solar cells and modules, were designed and constructed. These setups allow the simultaneous use of humidity, temperature, electrical biases, and illumination as independently controlled stress factors. The setups and various experiments executed are presented.

In Situ Überwachung von der beschleunigten Leistungsabfall von Solarzellen und Modulen: eine Fallstudie für Cu (In, Ga) Se2 Solarzellen

The levelized cost of electricity (LCOE) of photovoltaic (PV) systems is determined by, among other factors, the PV module reliability. Better prediction ...

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass (ADG) Fresnel Lens for Concentrating Photovoltaics

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is composed of two materials, a plastic and an elastomer, whose dispersion characteristics (refractive index variation with wavelength) are different. We first designed the lens geometry and then used ray-tracing simulation, based on the Monte Carlo method, to analyze its performance from the point of view of both optical efficiency and the maximum attainable concentration. Afterwards, ADG Fresnel lens prototypes were manufactured using a simple and reliable method. It consists of a prior injection of plastic parts and a consecutive lamination, together with the elastomer and a glass substrate to fabricate the parquet of ADG Fresnel lenses. The accuracy of the manufactured lens profile is examined using an optical microscope while its optical performance is evaluated using a solar simulator for concentrator photovoltaic systems. The simulator is composed of a xenon flash lamp whose emitted light is reflected by a parabolic mirror. The collimated light has a spectral distribution and an angular aperture similar to the real Sun. We were able to assess the optical performance of the ADG Fresnel lenses by taking photographs of the irradiance spot cast by the lens using a charge-coupled device (CCD) camera and measuring the photocurrent generated by several types of multi junction (MJ) solar cells, which have been previously characterized at a solar simulator for concentrator solar cells. These measurements have demonstrated the achromatic behavior of ADG Fresnel lenses and, as a consequence, the suitability of the modelling and manufacturing methods.

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics

The achromatic doublet on glass (ADG) Fresnel lens makes use of two materials with differing dispersion to reduce chromatic aberration and increase attainable concentration. In this paper, a protocol for the complete characterization of the ADG Fresnel lens is presented.

Indoor experimentelle Bewertung der Effizienz und der Bestrahlungsstärke vor Ort von der achromatischen Doublet auf Glas (ADG) Fresnel-Linse für die Konzentration Photovoltaik

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is ...

Developing High Performance GaP/Si Heterojunction Solar Cells

To improve the efficiency of Si-based solar cells beyond their Shockley-Queisser limit, the optimal path is to integrate them with III-V-based solar cells. In this work, we present high performance GaP/Si heterojunction solar cells with a high Si minority-carrier lifetime and high crystal quality of epitaxial GaP layers. It is shown that by applying phosphorus (P)-diffusion layers into the Si substrate and a SiNx layer, the Si minority-carrier lifetime can be well-maintained during the GaP growth in the molecular beam epitaxy (MBE). By controlling the growth conditions, the high crystal quality of GaP was grown on the P-rich Si surface. The film quality is characterized by atomic force microscopy and high-resolution x-ray diffraction. In addition, MoOx was implemented as a hole-selective contact that led to a significant increase in the short-circuit current density. The achieved high device performance of the GaP/Si heterojunction solar cells establishes a path for further enhancement of the performance of Si-based photovoltaic devices.

Here, we present a protocol to develop high-performance GaP/Si heterojunction solar cells with a high Si minority-carrier lifetime.

Entwicklung von Hochleistungs-Lücke/Si Heterojunction Solarzellen

To improve the efficiency of Si-based solar cells beyond their Shockley-Queisser limit, the optimal path is to integrate them with III-V-based solar ...