Materials Science

Interrelations between the properties of impurities and hosts in novel optical materials: fundamental and applied aspects

The project will be focused on complex experimental and theoretical studies of the fundamental and applied aspects of interactions between dopant ions (emitting centres) and crystalline host materials. Several groups of isostructural compounds are selected for this purpose to study effects of cation substitution or solid solution on the electronic and optical properties of the neat and doped materials. The influence of defects or chemical bonds between impurity ions and ligands on the luminescence properties and energy transfer efficiency will be considered. The project’s applied aspects are related to the use of the studied systems in lighting and scintillating devices, whereas the fundamental ones are aimed at identification and explanation of the relations between the optical properties of the studied materials and their structure and chemical composition. As a result, novel optical materials with improved characteristics for lighting and scintillating applications will be proposed.
     Principal investigator Prof Mikhail Brik, Laboratory of Physics of Ionic Crystals

Thin-film structures for nanoelectronic applications and functional coatings

The research aims at improving the existing techniques and developing new methods for preparation of high-quality thin-film structures that contain ultrathin solid films and/or nano-clusters and could be applied in (i) capacitor structures of next-generation dynamic random access memories, (ii) resistivity-switching memory structures (memristors), (iii) flash memories, (iv) gate stacks of field effect transistors with novel high-mobility channel materials, (v) spintronic devices and (vi) functional surface coatings such as diffusion barriers, surface-passivating, anticorrosion and biocompatible coatings. Different material technologies, incl. those suitable for preparation of graphene and nanoparticles, will be combined in the research whereas atomic layer deposition that allows atomic-layer level control of material synthesis will be used as the main technique to deposit ultrathin layers of solid-state structures for various applications.
     Principal investigator Prof Väino Sammelselg, Department of Materials Science

Nanomaterials – research and application

The aim of the project is to increase application efficiency of infrastructure developed within Estonian Research Infrastructures Roadmap project „Nanomaterials – research and application“ for co-operative research of project partners in the field of preparation and characterization of nanomaterials in order to improve conditions for high-level research and development and involve more experienced and young researchers to this field, and support knowledge trasfer inside Estonia as well as to Estonia. Within the project, preparation and characterization methods of nanomaterials and nanostructures will be advanced, training of high-level experts will be performed in order to fulfill requirements of Estonian research and development institutions and local high-technology industry, and high-level research service will be provided for infrastructure partners in the field of high-technology materials.
     Principal investigator Prof Jaan Aarik, Laboratory of Thin Film Technology

Transformation of electronic excitations into luminescence and radiation defects in wide-gap functional materials

The main features of intrinsic electronic excitations (EE) and their transformation into luminescence or nanosize structural defects in complex inorganic wide-gap materials (WGM) with many atoms per unit cell will be clarified. Recently complex WGM (incl. caged ones) have find use in many applications (fast scintillators for medicine and safety inspection, environmental friendly lighting, personal dosimeters etc) in the form of crystals, ceramics, films and nanomaterials. The main goals are to elucidate: (i) the evolution (from femtoseconds) of various EE formed at the irradiation by photons (up to 2000 eV), electrons and swift heavy ions, (ii) the excitonic and ionization mechanisms of radiation phenomena, especially at high EE density; (iii) the peculiarities of EE and their transformation in novel nanomaterials, optical ceramics and films synthesized in Tartu and abroad (iv) prospects and ways of increasing the radiation resistance and useful luminescence efficiency in complex WGM.
     Principal investigator Prof Aleksandr Luštšik, Laboratory of Physics of Ionic Crystals

Structure sensitive interaction mechanisms in functional materials at nanoscale

Application of nanotechnology depends strongly on structure-dependent properties of various nanostructures. Without better understanding and ability to predict structure-properties relations the nanotechnology will hardly reveal its full potential. We focus on studying structure-properties relations mainly of technologically important carbon-based, oxides, and some complex nanostructures. We will uniquely combine precise sample preparation, high resolution microanalysis, nanomechanical manipulation, and synchrotron based research that enables determination of structural characteristics such as surface composition, defects, internal structure etc. from a new perspective tailoring these back to properties such as mechanical, electrical, and optical characteristic of nanostructures. This approach enables significant progress in advanced modeling of structure formation and structure-properties relations that in turn will have a significant impact on development of new technologies.
     Principal investigator Prof Ergo Nõmmiste, Laboratory of X-Ray Spectroscopy