Projects

International

Optimalizácia škálovateľného rastu tenkých vrstiev dichalkogenidov prechodných kovov a nové heterostruktúry na použitie v elektronike a pokročilé senzory
Optimization of the scalable growth of transition metal dichalcogenide thin films and novel heterostructures for application in electronics and advanced sensors
Program: Bilateral – other
Project leader: Mgr. Sojková Michaela, PhD.
Duration: 1.1.2021 – 31.12.2022

National

CERBERUS – Farebné centrá v diamante – korelácia medzi atómovou štruktúrou a optoelektronickými vlastnosťami
Colour centres in diamond – correlation between atomic structure and opto-electronic properties
Program: SRDA
Project leader: Ing. Varga Marian, PhD.
Annotation: The subject of the project is in the field of quantum technologies. We will prepare and characterize optically -activedefects in diamonds and correlate the atomic structures with optical properties to be used for quantum applicati ons.For a wide range of dopant concentrations, we will identify the dopant distributions and study the evolution ofdopants’ configuration in-situ, during thermal annealing, using atomic-resolution microscopy and spectroscopytechniques. We will further study the effect of annealing on the opto-electronic properties by measuringphotoluminescence, photocurrent and electroluminescence for the same set of samples. Graphene transparentelectrodes on a diamond surface will be fabricated for phototransport measurements. Diamond-based hybrid p-i-ndiodes will be prepared for electroluminescence measurements. We will focus on finding a correlation between theatomic structure and the opto-electronic properties of differently doped diamonds. This will contribute to theunderstanding of the fundamental relationship needed to efficiently design optically -active elements for diamondquantum devices.
Duration: 1.9.2024 – 31.12.2027
PEROVCHIR – Vplyv aplikácie organických molekúl na vlastnosti perovskitovských tenkovrstvových štruktúr
Effect of the application of organic molecules on the properties of perovskite thin-film structures
Program: SRDA
Project leader: RNDr. Španková Marianna, PhD
Annotation: In recent years, sufficient experimental evidence has accumulated that adsorbed organic chiral molecules affectthe superconducting properties of YBa2Cu3O7-x (YBCO) films. In some cases, an increase in their critical temperature Tc can be observed. On the other hand, it has been shown that in the case of ferromagnetic layers (e.g., cobalt), the application of chiral molecules can lead to a change in magnetization without the use of an electric current. An important role here is played by spin. Spin introduces an additional degree of freedom into the system, allowing devices, for example, to reduce electrical consumption or increase their computational capacity. Spintronic devices have become an attraction in electronics; however, problems associated with controlling spin remain a significant challenge. A unique way of manipulating spin is through the effect known as chirality-induced spin selectivity (CISS), which results from the specific structure of organic chiral molecules. The project focuses on the preparation and characterization of simple heterostructures and their interaction with chiral polymers deposited on the film surface. Specifically, it deals with the influence of chiral lactic acid on perovskite thin films, where the selected perovskites are high-temperature superconductor YBCO and ferromagnet La1-xSrxMnO3 (LSMO).
Duration: 1.7.2024 – 31.12.2027
ROTOLES – Optimalizovaný rast a transportné a optické vlastnosti tenkých vrstiev vybraných topologických polokovov
Optimised growth and the transport and optical properties of thin layers of selected topological semimetals
Program: SRDA
Project leader: Dr. rer. nat. Hulman Martin
Annotation: One of the fundamental results of quantum mechanics in the 1920s was the derivation of relativistic equations formassive fermions (Dirac), massless fermions (Weyl) and fermions that are themselves antiparticles (Majorana).Since those times, particle physics has been searching for particles representing Weyl and Majorana\’s fermions.However, their search has not yet been successful.In the last twenty years, it has been shown that the band structure of some materials has such uniquecharacteristics that the charge carriers in them can behave according to the dynamics satisfying the Dirac or Weylrelativistic equations. Such materials include compounds from the group of transition metals dichalcogenides,which we will focus on in our project.We will work with very thin layers of selected materials from this group, such as PtSe2, MoTe2 and WTe2. The firststep in the implementation of the project will be the preparation of such layers by chalcogenisation of thin films oftransition metals. Their transport and optical properties will then be thoroughly investigated. Temperaturedependent transport measurements can show us transitions between different structures of the same material. We expect that a metal-insulator transition can be observed when the thickness of such thin films is varied. Some ofthese materials can go into a superconducting state at very low temperatures. We will also try to induce this state inclose proximity, i.e. when the thin layer is in contact with another superconductor.Optical measurements will be correlated with transport measurements. We derive essential frequency-dependentcharacteristics, such as optical conductivity, from the latter. We will look for characteristics theoretically predictedfor Dirac and Weyl fermions in the optical conductivity.
Duration: 1.7.2024 – 30.6.2027
Nanoelsen – Nanoštrukturované tenkovrstvové materiály vyznačujúce sa slabými väzbovými interakciami pre elektronické a senzorické aplikácie
Nanostructured thin-film materials characterized by weak binding interactions for electronic and sensoric applications
Program: SRDA
Project leader: RNDr. Gregušová Dagmar, DrSc.
Annotation: The proposed project is focused on the basic research of the preparation processes and properties ofsemiconducting sulfides of transition metals such as Mo, W and Ni and selected combinations with their oxides inthe form of mixed sulfides and oxides, as well as the possibilities of their doping with noble metals (Pt, Au) for usein gas sensors as well as in supercapacitors. We also anticipate full utilization of semiconductormicroelectronic and micromechanical techniques and micro / nanotechnologies, which can significantly contributeto qualitatively improved detection properties, low operating power consumption of gas sensors as well asincreased energy efficiency and supercapacitor lifetime.
Duration: 1.7.2022 – 30.6.2026
Transit2D – Tranzistory na báze 2D kovových chalkogenidov pripravených teplom podporovanou konverziou
Transistors based on 2D Metal Chalcogenides Grown via Thermally Assisted Conversion
Program: SRDA
Project leader: Ing. Ťapajna Milan, PhD.
Annotation: 2D materials can form one-atom-thick sheets with extraordinary properties. One of the most promising classes of2D materials is the transition metal dichalcogenides (TMDs). The transition from an indirect to a direct bandgap,when the bulk materials is thinned down to a monolayer, results in unique electrical and optical properties of 2DTMDs. Post-transition metal chalcogenides (PTMCs) represents another interesting group of 2D materials. Thesematerials have wide band gap and, depending on the structure of the material, show anisotropic electrical andoptical properties. The aim of this project is the fabrication of field-effect transistors with metal-oxide-semiconductorgate (MOSFETs) based on selected TMDs and PTMCs compounds and detail analysis of their transport properties.We will focus on large-area few-layer PtSe2 and GaS/GaSe films grown by thermal assisted conversion, i.e.sulfurization and selenization. Based on the existing experiences, structural, chemical and electrical properties ofhorizontally-aligned PtSe2 films prepared by selenization will be optimized, targeting mobilities similar to thoseprepared by mechanical exfoliation. Then, MOSFET technology using both, top-gate as well as bottom-gateapproach will be developed and optimized. Atomic layer deposition and metal-oxide chemical vapor deposition(MOCVD) will be employed for gate oxide growth. GaS/GaSe few-layer films will be prepared by chalcogenization
Duration: 1.7.2022 – 30.6.2026
Príprava, charakterizácia a dopovanie ultratenkých vrstiev dichalkogenidov prechodných kovov
Fabrication, characterization, and doping of ultra-thin layers of transition metal dichalcogenides
Program: VEGA
Project leader: Mgr. Sojková Michaela, PhD.
Annotation: Thanks to the unusual physical properties, 2D materials have been intensively studied for several years. Aninteresting group of this class of materials is transition metal dichalcogenides TMD. They have a hexagonalstructure with the individual layers bonded to each other only by weak Van der Waals bonds. This causessignificantly anisotropic properties and has a significant effect on their electronic structure. Some of them showphysically interesting correlated states (superconductivity, charge density waves). The primary goal of this projectis to prepare and study the properties of thin layers of 2 different TMD – MoS2 and PtSe2, and to study theinfluence of doping with Li and Na cations on the electrical and structural properties of these layers. Thesecondary goal is to optimize growth and doping conditions to improve the parameters of thin films, such aselectrical conductivity and charge carrier mobility which will enable the preparation of functional electroniccomponents – transistors.
Duration: 1.1.2021 – 31.12.2024
TMD2DCOR – Metalické 2D dichalkogenidy prechodných kovov: príprava, štúdium vlastností a korelované stavy
Fabrication, physics and correlated states in metallic 2D transition metal dichalcogenides
Program: SRDA
Project leader: Dr. rer. nat. Hulman Martin
Annotation: The discovery of graphene in 2004 has brought a massive interest of scientists active in condensed-matter physicson research of 2D materials. Even though these materials have a long history starting already in the twenties of the20th century, the past years have seen an intensive renascence of interest in 2D materials. Ultra-thin samples ofmany 2D materials have been successfully prepared with electronic properties that may exhibit correlatedelectronic phenomena such as charge density waves and superconductivity. One of the well-studied families of the2D materials are transition metal dichalcogenides (TMDs). TMDs consist of hexagonal layers of metal atomssandwiched between two layers of chalcogen atoms with a MX2 stoichiometry.In this project, we focus on those materials from the TMD family that exhibit strongly correlated electronic states:NbSe2, TiSe2, TaS2, TaSe2 and PtSe2. The goal of the project is to prepare ultrathin (≤ 10 nm) layers and bulksamples and characterise them thoroughly in terms of the thickness, crystallinity, homogeneity, optical andelectronic properties. A special attention will be paid to charge density wave states and superconductivity in thesematerials and how they evolve with the sample thickness, doping, external electric and magnetic fields and detailsof the growth process.The scientific program also aims at preparing heterostructures built up of these materials as well as hybrid systemscombining TMDs with other materials. This research also includes a detailed characterisation of heterostructures toprovide a feedback to optimise the growth process.
Duration: 1.7.2020 – 30.6.2023
2D materiály a iónové kvapaliny pre využitie v mikroelektronike a senzorike
2D materials and ionic liquids in microelectronics and sensors
Program: VEGA
Project leader: Mgr. Sojková Michaela, PhD.
Annotation: Two-dimensional (2D) materials and nanoparticles are a very hot topic. Project proposal builds on our knowledgegathered so far and it is focused on fabrication of 2D materials and nanoparticles (using ionic liquids ILs) and thecombination of three materials. The aim of the project is the fabrication of experimental materials and devices forsensors. Concerning 2D materials, we will focus on the optimization of the growth parameters of thin films ofselected materials. In field of nanoparticles, we will continue to prepare facetted metallic and carbonnanoparticles. Facetted ones will be used for the decoration of thin film 2D materials influencing thus the electricaltransport within the film, which is applicable e. g. in gas sensors. Carbon nanoparticles are fluorescent whichimplies their suitability for the use in fluorescence microscopy. The ionic liquids will be used both for preparationof nanoparticles in vacuum and also for formation of EDL gate to control the electrical transport in 2D materials.
Duration: 1.1.2017 – 31.12.2020