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Colourful nanoscale Lego blocks in play in photonic applications

Extremely thin and well organized structures are needed in photonic applications, such as solar cells, sensors and consumer electronics. When working in nanoscale, designing starts from the atomic and molecular levels.

In her dissertation, MSc (Tech) Essi Sariola-Leikas facilitates this process.

“The self-assembled molecules enable even multilayered thin film production through a simple procedure,” Essi Sariola-Leikas explains.

In her dissertation, Sariola-Leikas prepared various organic photoactive chromophores, including derivatives of chlorophyll. In these molecules, different types of anchor groups were attached. These anchors attached the molecules to the solid surfaces as uniform two-dimensional layers.

“Each surface material requires its own anchor group. Attachment to the surface takes place spontaneously. All we need to do is provide the molecules with favourable conditions for managing the process themselves,” Sariola-Leikas describes.

In the research, the molecules assembled on the surface in a controlled manner. With this simple technique, it was possible to prepare stable and colour-intensive samples that contained up to ten molecular layers. The layers were built like Lego towers, layer by layer. In this method, the metal-ligand interaction was utilized.

“This study represents basic research in supramolecular chemistry. The targets include applications in which these photoactive structures can be used. Research towards this goal is ongoing,” Sariola-Leikas says.

Public defence of a doctoral dissertation on Friday, 20 November

MSc (Tech) Essi Sariola-Leikas’ doctoral dissertation in the field of chemical engineering entitled ’Organic Chromophores in Self-Assembled Monolayers and Supramolecular Arrays‘ will be publicly examined at the Faculty of Natural Sciences of Tampere University of Technology (TUT) in auditorium Pieni Sali 1 in the Festia building (address: Korkeakoulunkatu 8, Tampere, Finland) at 12 noon on Friday, 20 November 2015.

The opponent will be Professor Nagao Kobayashi (Shinshu University, Japan). Adjunct Professor Alexander Efimov from the Department of Chemistry and Bioengineering at TUT will act as the Chairman.

Essi Sariola-Leikas (30) works as a researcher in the Supramolecular Photochemistry research group at the Department of Chemistry and Bioengineering of TUT.

Further information: Essi Sariola-Leikas, tel. +358 50 349 9052,

The dissertation is available online at:

News submitted by: Tiina Leivo
Keywords: science and research, photonics, self-assembled molecules, metal-ligand interaction, supramolecular chemistry