psi 19072011 300 17 20 6x2.jpg

The Thin Films and Interfaces Group

Thin films are nowadays utilized in many applications, ranging from semiconductor devices to optical coatings and are even present in pharmaceuticals (polymers). This wide-spread application of films with thicknesses from atomic monolayers to microns is due to the developments of thin film deposition techniques. Thin films are also important for studies of materials with new and unique properties due to the possibility of tuning their crystallographic and morphological properties. The thin film approach, i.e. the presence of interfaces (to a substrate or the film surface) adds more degrees of freedom for influencing the properties of materials, e.g. by lattice strain or surface functionalization. For these fundamental studies of material properties large research facilities such as synchrotron radiation or neutron spallation sources are one of the keys that the Paul Scherrer Institute (PSI) provides.

Our group focuses on the preparation of highly defined thin films by pulsed laser deposition (PLD) for applications in energy technology, but also for new properties, such as multiferroicity. We are working on the fundamental understanding of the PLD process, the influence of strain on material properties and we utilize the large facilities at PSI (neutrons, muons, and photons from the SLS). We therefore cooperate with many groups within the NUM, ENE and SYN divisions, and offer in addition a thin film deposition service. Top

Upcoming Group Seminars

All-Solid-State Li-ion Batteries Based on Garnet-Type Fast Li-ion Conductor Li7La3Zr2O12 - Abstract
Speaker: J. van den Broek
Date: Monday 12 December 2016 16:30
Room: OFLG/402

Spontaneous incorporation of silver particles in thiophene-based conducting polymers - Abstract
Speaker: R. Assunção
Date: 17:00
Room: OFLG/402

ENE-Seminar: Improving the ion conductivity by stretching the crystal lattice
Speaker: A. Fluri
Date: Thursday 15 December 2016 11:00
Room: OSGA/EG6

(Ba1−xCax)(ZryTi1−y)O3 processing by PLD and LIFT - Abstract
Speaker: Adrian-Ionut Bercea
Date: Monday 09 January 2017 16:30
Room: OFLG/402

Speaker: S. Mirkhanov
Date: 17:00
Room: OFLG/402

Speaker: D. Pergolesi
Date: Monday 23 January 2017 16:30
Room: OFLG/402


Most recent Paper

Sandra E. Temmel, Emiliana Fabbri, Daniele Pergolesi, Thomas Lippert, and Thomas J. Schmidt
Investigating the Role of Strain toward the Oxygen Reduction Activity on Model Thin Film Pt Catalysts
ACS Catalysis 6, 7566 (2016)

Environmentally friendly energy conversion devices such as fuel cells are becoming more and more attractive. However, major impediments to large-scale application still arise on the material side, related to the cost and poor performance of the cathode catalyst. State-of-the-art electrocatalysts are all Pt-based materials, suffering from poor electrochemical oxygen reduction kinetics. Tuning the interatomic distance of Pt atoms represents a promising strategy for reducing the strength of adsorption of oxygenated species to the Pt surface and thus improving the kinetics. In this context, model Pt electrocatalysts of straininduced varied interatomic spacing were fabricated and tested. Strained Pt films with high crystalline quality can be obtained via epitaxial growth on appropriate single-crystal substrates like (111) SrTiO3, which have lattice Parameters different from those of Pt using pulsed laser deposition. Through a proper selection of deposition parameters, the extent of strain in the Pt films can be controlled. This study shows that strain significantly modifies the electrochemical surface properties. In particular, cyclic voltammetry and CO oxidation experiments provide valuable insights into the effect of strain on the adsorption properties of spectator species (e.g., OHad and bisulfates) relevant for oxygen reduction reaction (ORR) kinetics. Furthermore, the strained Pt films exhibit a remarkably higher oxidation reduction reaction activity compared to that of the fully relaxed bulk structure as obtained from ORR polarization curves. This research highlights the importance of proper model systems with defined physical properties to establish design principles for better-performing catalysts.
Facility: ENE, Electrochemistry; LMX, Thin Films and Interfaces

Reference: S.E. Temmel et al, ACS Catalysis 6, 7566 (2016)

Read full article: here