Project

Back to overview

Low-Temperature Solution-Deposition of Core-Shell Particles on Flexible Substrates for Transparent Conducting Electrode Applications

English title Low-Temperature Solution-Deposition of Core-Shell Particles on Flexible Substrates for Transparent Conducting Electrode Applications
Applicant Niederberger Markus
Number 155658
Funding scheme precoR
Research institution Departement Materialwissenschaft ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Material Sciences
Start/End 01.01.2015 - 31.12.2016
Approved amount 229'050.00
Show all

All Disciplines (2)

Discipline
Material Sciences
Inorganic Chemistry

Keywords (6)

thin films; transparent conducting oxides; metal; core-shell particles; chemical solution deposition; metal oxide

Lay Summary (German)

Lead
Herstellung von transparenten, leitfähigen Schichten auf flexiblen Substraten aus Flüssigkeiten bei niedriger Temperatur
Lay summary

Transparente, leitfähige Oxide (sogenannte TCOs) sind Materialien, die sowohl elektrisch leitfähig wie auch transparent sind. Sie finden Anwendung in Solarzellen, Flachbildschirmen, oder in elektrochromen Fenstern. Das Marktvolumen wird auf mehrere Milliarden geschätzt.

In Flachbildschirmen wird heute hauptsächlich Indiumzinnoxid (ITO) verwendet. Technologisch werden diese Filme typischerweise mittels Gasphasenprozesse abgeschieden. Obwohl Gasphasenprozesse inzwischen optimiert sind, sind sie immer noch teuer und kompliziert. Abscheidung solcher TCO Filme aus Flüssigkeiten wäre viel billiger, da kein Vakuum wie bei Gasphasenprozessen nötig wäre, der apparative Aufwand wäre viel geringer und die Materialkosten wären viel niedriger.

Leider sind Filme aus der Flüssigphase qualitativ aber noch nicht gut genug. Vor allem die niedrige elektrische Leitfähigkeit stellt ein grosses Problem dar, das nur gelöst werden kann, indem die Filme bei mehreren Hundert Grad getempert werden. Für temperaturempfindliche Substrate wie Polymerfolien ist das aber keine Option.

In diesem Projekt geht es nun darum, Prozesse und Materialien zu entwickeln, die für die Flüssigphasen-Abscheidung von transparenten und leitfähigen Schichten auf flexiblen Substraten bei tiefer Temperatur verwendet werden können.

 

Direct link to Lay Summary Last update: 03.07.2014

Responsible applicant and co-applicants

Employees

Publications

Publication
Synthesis, Spray Deposition, and Hot-Press Transfer of Copper Nanowires for Flexible Transparent Electrodes
Deshmukh Rupali, Calvo Micha, Schreck Murielle, Tervoort Elena, Sologubenko Alla S., Niederberger Markus (2018), Synthesis, Spray Deposition, and Hot-Press Transfer of Copper Nanowires for Flexible Transparent Electrodes, in ACS Applied Materials & Interfaces, 10(24), 20748-20754.
Assembly of ultrasmall Cu3N nanoparticles into three-dimensional porous monolithic aerogels.
Deshmukh Rupali, Tervoort Elena, Käch Julian, Rechberger Felix, Niederberger Markus (2016), Assembly of ultrasmall Cu3N nanoparticles into three-dimensional porous monolithic aerogels., in Dalton transactions (Cambridge, England : 2003), 45(29), 11616-9.
Nonhydrolytic Sol-Gel Methods
Deshmukh Rupali, Niederberger Markus (2015), Nonhydrolytic Sol-Gel Methods, in Levy David (ed.), Wiley-VCH, Weinheim, 29-69.
Ultrasmall Cu3N Nanoparticles: Surfactant-Free Solution-Phase Synthesis, Nitridation Mechanism, and Application for Lithium Storage
Deshmukh Rupali, Zeng Guobo, Tervoort Elena, Staniuk Malwina, Wood David, Niederberger Markus (2015), Ultrasmall Cu3N Nanoparticles: Surfactant-Free Solution-Phase Synthesis, Nitridation Mechanism, and Application for Lithium Storage, in Chemistry of Materials, 27, 8282-8288.

Collaboration

Group / person Country
Types of collaboration
Prof. Tiwari/EMPA Dübendorf Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
MaP Graduate Symposium Talk given at a conference Synthesis and assembly of crystalline ultrasmall copper nitride particles into freestanding 3D aerogel 03.06.2016 Zurich, Switzerland Deshmukh Rupali Ganpat;
Materials Research Society Spring Meeting Talk given at a conference Solution-Phase Deposition of Metallic Copper on Cellulose Fibers and Their Processing int Conductive Paper or Mats 28.03.2016 Phoenix, United States of America Deshmukh Rupali Ganpat;
XVIII International Sol-Gel Conference Talk given at a conference Assembly of crystalline ulstrasmall Cu3N particles into freestanding 3D aerogel 06.09.2015 Kyoto, Japan Deshmukh Rupali Ganpat;
Materials Research Society Spring Meeting Talk given at a conference Ultrasmall copper nitride nanoparticles: Surfactant-free solution synthesis, nitridation mechanism and assembly 06.04.2015 San Francisco, United States of America Deshmukh Rupali Ganpat;


Abstract

Transparent conducting oxides (TCOs) are unique materials in the sense that they combine two opposing properties: Transparency in the visible light range and high electrical conductivity. They found widespread technological applications as transparent electrodes in solar cells, flat-panel displays, electrochromic windows and as low-emissivity coatings, just to mention a few. According to a recent IDTechEx report, the transparent conductive film and glass markets will grow from $1.63 billion in 2012 to $6.3 billion in 2014. With the emergence of transparent displays in 2012, market estimations even reached $87.2 billion by 2025.With the development of flat-panel display technology around 1970, indium tin oxide (ITO) became the most commonly used TCO material for transparent electrodes due to its low resistivity of the order of 1-2 x 10-4 O cm. The vast majority of TCO films are technologically produced by vapor phase techniques such as chemical vapor deposition or magnetron sputtering, and these processes have been fully optimized over the years. Nevertheless, they remain expensive and technically highly complex. Thin film deposition by solution routes, on the other hand, would be cheap, because no vacuum is required, no material is lost, complex compositional mixtures and a wide compositional range of materials could be used. However, whereas gas phase processes produce continuous, dense and homogeneous films with uniform thickness and low surface roughness, solution routes struggle with impurities and porosity in the films, which strongly affects their electrical conductivity. The only way to solve these problems is to apply a heat treatment to the films, burning off volatile impurities and enhancing the intergrain connectivity to improve the conductivity. Unfortunately, for thermally labile substrates like flexible plastics such a heat treatment is not an option.From these explanations it is obvious that liquid-phase deposition of TCO films at low temperature would technologically be extremely attractive, if the films could be prepared in sufficient quality. To solve the major problems of nanoparticle processing into films, we propose a new concept based on the combination of metals with metal oxides in a core-shell particle configuration. Both components specifically contribute to the TCO performance. The metal provides the conductive path for the electrons, and the metal oxide suppresses the color of the metal to make the film transparent. The use of metal oxide - metal composites avoids the temperature problem, because good electrical conductivity can be obtained without substrate heating. In addition, such a low temperature process would lead to strong reduction in energy consumption during thin film preparation.Specifically, the proposal suggests the development of a liquid-phase route to metal oxide particles coated with a thin layer of a metal, preferentially copper. These core-shell particles are deposited on flexible substrates by spin- or dip-coating. An additional metal oxide surface layer deposited on top of the film protects the copper from oxidation, decreases the surface roughness and increases the mechanical stability. Finally, these films will be tested as electrodes in solar-cell and organic light-emitting diode applications as a proof-of-concept for the success of this new fabrication technology.
-