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. Read more

News

15 November 2018

Woman in Science

Congratulations to our former postdoc, Alexandra Palla-Papavlu (4^th from the left), for winning the L’Oreal Prize for Woman in Science(link is external) in the category Physics in Romania

Upcoming Conferences

December 2019

2019 MRS Fall Meeting & Exhibit

December 01-06, 2019
Boston, Massachusetts, USA
More Information

Upcoming Seminars

Title: TBA
Speaker: V. Michel
Date: Monday 02 December 2019, 16:00
Room: OFLG/402
TFI-SEMINAR

Speaker:
Date: Tuesday 19 November 2019, 13:00
Room: OSGA/EG06
LMX-SEMINAR

Title: TBA
Speaker: N. Ohannessian
Date: Tuesday 17 December 2019, 10:30
Room: OFLG/402
TFI-SEMINAR

Scientific Highlights

11 February 2019

Electronic localization in CaVO₃ films via bandwidth control

Understanding and controlling the electronic structure of thin layers of quantum materials is a crucial first step towards designing heterostructures where new phases and phenomena, including the metal-insulator transition (MIT), emerge. Here, we demonstrate control of the MIT via tuning electronic bandwidth and local site environment through selection of the number of atomic layers deposited.

8 February 2019

Thermally activated two-dimensional artificial square ice with height offsets between nanomagnets.

(A) Tilted-sample scanning electron microscopy (SEM) image of an artificial square ice with an introduced height offset h, which can be varied from sample to sample, until the competing interactions J1 and J2 are equalized and an extensive spin ice degeneracy is achieved. Scale bar, 400 nm. (B) XMCD image of the same artificial square ice array. Nanomagnets with moments pointing toward the incoming x-rays (i…

Emergent magnetic monopole dynamics in macroscopically degenerate artificial spin ice

Magnetic monopoles, proposed as elementary particles that act as isolated magnetic south and north poles, have long attracted research interest as magnetic analogs to electric charge. In solid-state physics, a classical analog to these elusive particles has emerged as topological excitations within pyrochlore spin ice systems. We present the first real-time imaging of emergent magnetic monopole motion in a macroscopically degenerate artificial spin ice system consisting of thermally activated Ising-type nanomagnets lithographically arranged onto a pre-etched silicon substrate. factors are observed.

17 January 2019

Improved Photoelectrochemical Water Splitting of CaNbO₂N Photoanodes by CoPi Photodeposition and Surface Passivation

Photoelectrochemical (PEC) solar water splitting is a promising approach to convert solar energy into sustainable hydrogen fuel using semiconductor electrodes. Owing to their visible light absorption properties, oxynitrides have shown to be attractive photocatalysts for this application. In this study, the influence of the preparation method of CaNbO₂N particles on their morphological and optical properties, and thereby their PEC performance, is investigated. The best performing CaNbO₂N photoanode is produced by ammonolysis of Nb-enriched calcium niobium oxide.

4 January 2019

Oxynitride Thin Films versus Particle-Based Photoanodes: A Comparative Study for Photoelectrochemical Solar Water Splitting

The solar water splitting process assisted by semiconductor photocatalysts attracts growing research interests worldwide for the production of hydrogen as a clean and sustainable energy carrier. Because of their optical and electrical properties, several oxynitride materials show great promise for the fabrication of efficient photocatalysts for solar water splitting. This study reports a comparative investigation of particle- and thin-film-based photocatalysts using three different oxynitride materials.

4 December 2018

Scheme of the laser based methods applied for coating the SAW devices: MAPLE is used to fabricate in one step a polymer multi-ribbon, which is afterwards used as a donor for printing by LIFT of polymer pixels onto the SAW resonator. From Fig. 1

Highly selective surface acoustic wave e-nose implemented by laser direct writing

In this paper, we present an e-nose for the detection of volatile compounds based on an array of six surface acoustic wave (SAW) resonators coated with five different polymers (i.e. polyepichlorohydrin, polyisobutylene, polyethylenimine, (hydroxypropyl)methyl cellulose, and poly(styrene-co-maleic acid) partial isobutyl/methyl mixed ester, plus an uncoated SAW device used as reference.

31 October 2017

Special interview with Prof. Thomas Lippert and Prof. Tatsumi Ishihara

Special interview with Prof. Thomas Lippert (PSI and Principle Investigator at I²CNER, Kyushu University) and Prof. Tatsumi Ishihara (Associate Director I²CNER, Kyushu University) on Current and Future Energy Research and Development in Europe: Perspectives from Switzerland, Germany and Japan. The interview is being published in the August 2017 issue of the Energy Outlook of the International Institut for Carbon-Neutral Energy Research, I²CNER.

PhD projects at the Thin Films and Interfaces Group

At present, we have one open PhD positions available. Details are posted at our open position page. Other open positions are always published on the PSI Open Positions page.

Most Recent Publication

Yttrium Tantalum Oxynitride Multiphases as Photoanodes for Water Oxidation

Wenping Si, Zahra Pourmand Tehrani, Fatima Haydous, Nicola Marzari, Ivano E. Castelli, Daniele Pergolesi, and Thomas Lippert

Abstract:

The perovskite yttrium tantalum oxynitride is theoretically proposed as a promising semiconductor for solar water splitting because of the predicted band gap and energy positions of band edges. In experiments, however, we show here that depending on the processing parameters, yttrium tantalum oxynitrides exist in multiphases, including the desired perovskite YTaON₂, defect fluorite YTa(O,N,□)₄, and N-doped YTaO₄. These multiphases have band gaps ranging between 2.13 and 2.31 eV, all responsive to visible light. The N-doped YTaO₄, perovskite main phase, and fluorite main phase derived from crystalline fergusonite oxide precursors exhibit interesting photoelectrochemical performances for water oxidation, while the defect fluorite derived from low-crystallized scheelite-type oxide precursors shows negligible activity. Preliminary measurements show that loading an IrOx cocatalyst on N-doped YTaO4 significantly improves its photoelectrochemical performance, encouraging further studies to optimize this new material for solar fuel production.

Contact

Thin Films and Interfaces Group
Paul Scherrer Institut
5232 Villigen PSI
Switzerland
Homepage

Professor Dr. Dr. h.c. Thomas Lippert
Head of Group
OFLB/U110
tel: +41 56 310 4076
fax: +41 56 310 2688
thomas.lippert@psi.ch

Seminars

Thin Films and Interfaces Group Seminars
ENE Seminars
CMT seminar/journal club

The Thin Films and Interfaces Group

News

Woman in Science

Upcoming Conferences