Epitaxial growth and characterization of oxide and topological insulator thin films

The focus of our research are materials in thin film form, especially transition metal and rare-earth oxides as well as topological insulator compounds. Our state-of-art in-house ultra-high vacuum system consists of two molecular beam epitaxy chambers and five facilities for an in-situ characterization of the samples, including electron diffraction techniques (RHEED, LEED), photoelectron spectroscopy (XPS, ARPES), temperature-dependent resistivity measurements, and ionic liquid gating experiments.

The focus of our research are materials in thin film form, especially transition metal and rare-earth oxides which show metal-insulator transitions and interesting magnetic properties, as well as topological insulator compounds, materials having a full insulating gap in the bulk but a topologically protected conducting surface. The properties of these fascinating materials are governed by the interplay of complex interactions. Thin films and heterostructures offer a broad platform to tune these interactions, e.g. by strain, domain size, screening, proximity effects, and doping. This can provide important insights into the fundamental mechanisms that determine the properties of a material, and enables us to manipulate the characteristics of a material, for instance by inducing or suppressing phase transitions.  

Our state-of-art in-house ultra-high vacuum system allows for the growth and in-situ characterization of high-quality thin films. It includes two molecular beam epitaxy chambers: one for oxides and one for topological insulators. The films are investigated all under ultra-high vacuum conditions in five connected facilities: the crystal structure is studied using electron diffraction techniques (RHEED, LEED), the electronic structure of bulk and surface by photoelectron spectroscopy (XPS, ARPES), and the transport behavior by temperature-dependent resistivity measurements. In a new experimental setup also in-situ ionic liquid gating experiments can be performed.

Go to Editor View