Pārejas metālu halkogenīdus saturošu kodola-apvalka nanovadu sintēze un īpašības
Elektroniskā versija nesatur pielikumus
Towards metal chalcogenide nanowire-based colour-sensitive photodetectors
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2016/6 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Authors are grateful to Reinis Ignatans for XRD measurements.
Nanoscale X-ray detectors based on individual CdS, SnO2 and ZnO nanowires
Abstract The development of nanoscale X-ray sensors is of crucial importance to achieve higher spatial resolution in many X-ray-based techniques playing a key role in materials science, healthcare, and security. Here, we demonstrate X-ray detection using individual CdS, SnO 2 , and ZnO nanowires (NWs). The NWs were produced via vapor–liquid–solid technique and characterized using X-ray diffraction, scanning, and transmission electron microscopy . Electrical measurements were performed under ambient conditions while exposing two-terminal NW-based devices to X-rays generated by a conventional tungsten anode X-ray tube. Fast and stable nanoampere-range X-ray beam induced current (XBIC) in resp…
Synthesis and characterization of GaN/ReS2, ZnS/ReS2 and ZnO/ReS2 core/shell nanowire heterostructures
This research was funded by the ERDF project “Smart Metal Oxide Nanocoatings and HIPIMS Technology”, project number: 1.1.1.1/18/A/073. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART².
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Financial support provided by Scientific Research Project for Students and Young Researchers, Latvia Nr. SJZ/2018/7 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.
Unexpected Epitaxial Growth of a Few WS2 Layers on {11̅00} Facets of ZnO Nanowires
Core–shell nanowires are an interesting and perspective class of radially heterostructured nanomaterials where epitaxial growth of the shell can be realized even at noticeable core–shell lattice mismatch. In this study epitaxial hexagonally shaped shell consisting of WS2 nanolayers was grown on {1100} facets of prismatic wurtzite-structured [0001]-oriented ZnO nanowires for the first time. A synthesis was performed by annealing in a sulfur atmosphere of ZnO/WO3 core–shell structures, produced by reactive dc magnetron sputtering of an amorphous a-WO3 layer on top of ZnO nanowire array. The morphology and phase composition of synthesized ZnO/WS2 core–shell nanowires were confirmed by scanning…
A comparative study of heterostructured CuO/CuWO4 nanowires and thin films
Authors are grateful to Reinis Ignatans for XRD measurements.
Excited States Calculations of MoS2@ZnO and WS2@ZnO Two-Dimensional Nanocomposites for Water-Splitting Applications
This research was funded by the Latvian Scientific Council grant LZP-2018/2-0083. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union's Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.
Kinking in Semiconductor Nanowires: A Review
The growth direction of nanowires (NWs) can change during synthesis as a result of stochastic processes or modulation of certain growth conditions. This phenomenon is known as kinking. Although deviations from a uniform vertical growth are typically considered to be undesirable, kinking opens a route for additional tweaking of the characteristics and functionalities of NWs in a controllable manner, thus extending the range of potential applications. In the present Review, we give an insight into the kinking mechanisms and summarize the most crucial factors that can lead to kinking of NWs during synthesis. Additionally, the properties and applications of kinked NWs are discussed. © 2021 The …
Pārejas metālu halkogenīdu 1D un 2D nanostruktūru sintēze un raksturošana
Darbā tiek aplūkotas divdimensiju (2D) pārejas metālu halkogenīdu - volframa un molibdēna disulfīdu - īpašības un iegūšanas metodes. Ir demonstrēta šo 2D mikrokristālu sintēzes metode no gāzveida reaģentiem, kā arī izstrādātas jaunas metodes viendimensiju (1D) metālu oksīdu nanovadu core-shell heterostruktūru izgatavošanai, veidojot plānus disulfīdu pārklājumus uz ZnO nanovadiem, izmantojot ar reaktīvo magnetrona izputināšanu iegūtu pārklājuma sulfurēšanu vai attiecīgo pārejas metālu amonija sāļu pārklājuma termolīzi gāzveida sēra klātbūtnē. Iegūtās nanostruktūras tika izgatavotas un raksturotas, izmantojot LU CFI pieejamās zinātniskās iekārtas. Darbs sastāv no literatūras apskata un eksper…
Dažādas HOPG gravēšanas metodes grafēna uznešanai uz Si pamatnes
Darbā apskatītas un pētītas dažādas augstas sakārtotības pirolītiskā grafīta (HOPG) gravēšanas metodes vēlamā virsmas raksta izveidošanai, kā arī izveidotas un attīstītas metodes grafēna lokšņu uznešanai uz dielektriskas pamatnes ar dažādiem spiedogiem. Gravēto HOPG struktūru kvalitātes raksturošanai, uz pamatnes uznesto grafēna lokšņu vizualizācijai un to biezuma noteikšanai tika izmantotas dažādas LU CFI pieejamās zinātniskās iekārtas. Darbs sastāv no literatūras pārskata daļas un no eksperimentālās daļas, kur aprakstītas izmantotās gravēšanas metodes, spiedogu izgatavošana, grafēna mehāniskās kontaktpārnešanas metodes un ietverti sasniegtie rezultāti. Pilnveidojot šādu ātru, vienkāršu un…
Effect of DNA Aptamer Concentration on the Conductivity of a Water-Gated Al:ZnO Thin-Film Transistor-Based Biosensor
This research was supported by State Education Development Agency, Project No. 1.1.1.2/ 16/I/001, Research Proposal No. 1.1.1.2/VIAA/4/20/590 “Portable diagnostic device based on a biosensor array of 2D material sensing elements”.
Understanding the Conversion Process of Magnetron-Deposited Thin Films of Amorphous ReO$_x$ to Crystalline ReO$_3$ upon Thermal Annealing
Crystal growth & design 20(9), 6147 - 6156 (2020). doi:10.1021/acs.cgd.0c00848
Unraveling the Structure and Properties of Layered and Mixed ReO3–WO3 Thin Films Deposited by Reactive DC Magnetron Sputtering
Tungsten trioxide (WO3) is a well-known electrochromic material with a wide band gap, while rhenium trioxide (ReO3) is a “covalent metal” with an electrical conductivity comparable to that of pure metals. Since both WO3 and ReO3 oxides have perovskite-type structures, the formation of their solid solutions (ReO3–WO3 or RexW1–xO3) can be expected, which may be of significant academic and industrial interest. In this study, layered WO3/ReO3, ReO3/WO3, and mixed ReO3–WO3 thin films were produced by reactive DC magnetron sputtering and subsequent annealing in air at 450 °C. The structure and properties of the films were characterized by X-ray diffraction, optical spectroscopy, Hall conductivity…
Fast-Response Single-Nanowire Photodetector Based on ZnO/WS 2 Core/Shell Heterostructures
This work was supported by the Latvian National Research Program IMIS2 and ISSP project for Students and Young Researchers Nr. SJZ/2016/6. S.P. is grateful to the ERA.Net RUS Plus WATERSPLIT project no. 237 for the financial support. S.V. is grateful for partial support by the Estonian Science Foundation grant PUT1689.
Growth and characterization of PbI2-decorated ZnO nanowires for photodetection applications
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/1 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. The authors are grateful to Liga Bikse for XRD measurements.
The Effect of a Nucleation Layer on Morphology and Grain Size in MOCVD-Grown β-Ga2O3 Thin Films on C-Plane Sapphire
This research is funded by the Latvian Council of Science project “Epitaxial Ga2O3 thin films as ultrawide bandgap topological transparent electrodes for ultraviolet optoelectronics” No. lzp-2020/1-0345. S.O. was supported by the European Union’s Horizon 2020 program, under Grant Agreement No. 856705 (ERA Chair “MATTER”). Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART².
Synthesis and characterization of ZnO/ZnS/MoS2 core-shell nanowires
The present research was supported by the Latvian National Research Program IMIS2 . Authors are grateful for Dr. Robert Kalendarev and Martins Zubkins for assistance in magnetron sputtering, Dr. Krisjanis Smits for TEM measurements, Dr. Roberts Zabels for AFM measurements and Reinis Ignatans for XRD measurements.