International
Pulzná laserová depozícia 2D polovodičov na nitridy pre pokročilú elektroniku | |
PULSEd laser deposition of 2D semiconductors on nitrides for advanced electronics | |
Program: | Bilateral – other |
Project leader: | RNDr. Španková Marianna, PhD |
Duration: | 1.1.2021 – 31.12.2022 |
National
TECHAPHO – Ternárne chalkogenidové perovskity pre fotovoltaiku | |
Ternary chalcogenide perovskites for photovoltaics | |
Program: | SRDA |
Project leader: | Ing. Chromik Štefan, DrSc. |
Annotation: | The goal of the proposed project is the synthesis of ternary chalcogenides with perovskite structure and systematiccharacterization of the relationship between the composition, structure, optical properties, thermal and chemical stability with the potential in the application in photovoltaics, or other optoelectronics. The result will be a set of prepared pure ternary chalcogenides in the form of crystalline powders and thin films with known, as well as newly prepared compositions and a comprehensive characterization of their optical and electronic properties, as well as thermal and chemical stability. Ternary chalcogenides will be prepared also by wet approach at lower temperature up to 350 °C in the form of nanocrystals which will be characterized in terms of their structure and morphology.Proof-of-concept solar cell will be prepared, which has not yet been reported in the literature. The optimalization will be done based on performance measurements. |
Duration: | 1.7.2024 – 30.6.2028 |
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 |
Modifikácia vlastností supravodivých, feromagnetických oxidových vrstiev a štruktúr pre modernú elektroniku | |
Modification of properties of superconducting, ferromagnetic, oxide films and structures for advanced electronics | |
Program: | VEGA |
Project leader: | RNDr. Španková Marianna, PhD |
Annotation: | We prepare and study oxide – ferromagnetic and dielectric perovskite thin films and micro- and nano structures as well as selected current superconducting films. YBa2Cu3Ox (YBCO) and La0.67Sr0.33MnO3 (LSMO) microstrips will be exposed different types of organic molecules to study their influence on the superconducting and ferromagnetic film properties. Following the results of the previous VEGA project, we will continue to study the superconductor S/ferromagnet F and S/F/S structures focusing on a creation of magnetic inhomogeneities with the aim to increase the triplet component of superconductivity and resolve the phenomenom of S/F thin films interaction (proximity effect). As part of the project, we will investigate the possibility of superconducting behavior of a two-dimensional MoS2 system deposited by pulsed laser deposition. |
Duration: | 1.1.2022 – 31.12.2025 |
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 |
Perovskitovské tenké vrstvy a štruktúry vhodné pre modern elektroniku a senzoriku | |
Perovskite thin films and structures for modern electronics and sensorics | |
Program: | VEGA |
Project leader: | RNDr. Španková Marianna, PhD |
Annotation: | We prepare different types of perovskite films -ferromagnetic, superconducting, dielectric- (thickness up to 100nm) and micro- and nano structures. YBa2Cu3Ox superconducting microstrips will be irradiated by electrons (30keV) with the aim to create channels for easy vortex motion. We also focus on detailed study of Si/dielectric layerinterface using unconventional materials (SrO, TiN) with the aim to enable epitaxial growth of buffer layersnecessary for realization of uncooled microbolometers on the base of La0.67Sr0.33MnO3 films working and atfrequencies in THz range. Beside the Bi4Ti3O12 studied so far different types of other buffer layers will be testedin order to develop new types of bolometers. We continue in study of perovskite superconductor S/ferromagnet Fand S/F/S structures with the aim to resolve the phenomenom of S/F thin films interaction (proximity effect). Theimplementation of pi-type Josephson junction in digital and quantum circuits may solve some problems of superconducting qubits. |
Duration: | 1.1.2018 – 31.12.2021 |