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PhD thesis defense of Wouter Marchal

PhD thesis defense of Wouter Marchal

Jan 26, 2018 - 16.15 uur

Oude Gevangenis

Universiteit Hasselt

campus Hasselt

Martelarenlaan 42

3500 Hasselt

Lokaal auditorium Louis Roppe

Wouter Marchal invites you to the public defense of his doctoral thesis entitled: "Redox mechanisms in low-temperature solution processing of materials for flexible electronics".

Promoter is Prof. Dr. An Hardy.

Co-promoter is Prof. Dr. Marlies K. Van Bael


In the past 4 years, we focused on the chemical deposition of materials for flexible electronics. Imagine that we would be able to print electronic circuit components such as solar cells, light emitting diodes or just miniscule patterned conductive tracks on paper, plastic or textile. In this way we could make a lot of everyday objects ‘smart’. For instance, a blanket with a printed solar panel on top to charge your electric car when it is parked, which you can fold and store in your trunk if you want to drive away.

However, to enable these smart solutions, we need to find a way to coat and deposit materials like metals and transparent conductive oxides on temperature-sensitive substrates (e.g. plastics). To achieve this target, we investigated two different ‘chemical tricks’, which convert the liquid we want to use for printing/coating into the desired functional material.

The first chemical trick is based on the same ingredients you use to create an explosion, but then applied on a micro- and nano-scale. In this way, the targeted oxides can possibly form because of local internally generated heat, instead of an externally applied temperature treatment which would destroy the plastic/paper substrate. However, we found that this reaction mechanism can only occur within some clear boundary conditions related to the material dimensions, the temperature treatment and the occurrence of side-reactions.

The second chemical trick was applied to create metal features from solutions you can put in an inkjet printer. We unraveled the mechanism of how this conversion from an innovative designed ink on to a conductive metal layer occurs on plastic. This step can help other researchers in their ink formulation experiments, and contributes to the promising future of printable electronics.

From now on, the research can extend to the optimization of the ink for industrial processes, but also the development of alloy inks or 3D printing applications. In addition, the transparent oxide materials can be fine-tuned (both in composition and morphology) to further increase the efficiency of flexible solar cells and light emitting devices.