10 research outputs found
1.55 um electroluminescence from strained n-Ge quantum wells on silicon substrates
No full textElectroluminescence from strained n-Ge quantum wells LEDs on Si0.05Ge0.95 are demonstrated. Electroluminescence characterisation demonstrates two peaks around 1.55 μm and 1.8 μm, which correspond to transitions between the direct and indirect transitions respectively
Measurement of the lifetime of photo-generated free carriers in Si-Ge waveguides
No full textThe carrier lifetime in SiGe planar waveguides with Si cladding was measured with a pump-and-probe technique, using an ultrashort 810 nm laser pulse and a CW 1.55 mu m probe, as a function of layer thickness d and Ge concentration x. The measured lifetimes are in the range of 20-90 ns. The obtained interface recombination velocity S is a growing function of both d and x, taking values in the range from 300 to 4000 cm/s
The Spatial Plan of the City of Uherske Hradiste with Focus on Public Green Areas with a Predominance of Unpaved Areas
No full textV teoretické části práce na téma "Územní plán města Uherské Hradiště (se zaměřením na plochy veřejných prostranství s převahou nezpevněných ploch)" se autorka věnuje nástro-jům, kterými je zajištěna ochrana životního prostředí v procesu územního řízení probíhají-cího dle zákona č. 183/2006 Sb., o územním plánování a stavebním řádu, přičemž za zá-kladní nástroj považuje pořízení územního plánu. V praktické části práce se pak již zabývá územním plánem Uherského Hradiště, a to průběhem jeho pořízení, souladem s dalšími územně analytickými podklady a zejména plochami veřejných prostranství s převahou ne-zpevněných ploch, které jsou určeny pro veřejnou zeleň (parky a zalesněná území, např. lokalita architektonického naleziště Sady a bývalého židovského hřbitova). U jednotlivých ploch se autorka zajímá o to, zda byl naplněn jejich hlavní účel, tj. umístění zeleně, včetně druhu a množství, a zda jsou zde i jiné přípustné prvky drobné architektury či technické infrastruktury.In the theoretical part of the thesis "The Spatial Plan of the City of Uherske Hradiste with Focus on Public Green Areas with a Predominance of Unpaved Areas" the author describes the tools which ensures the protection of the environment in the process of land management according to the Czech Act no. 183/2006 Sb., Construction Act, while an essential tool is the spatial plan (city plan). In the practical part of the thesis the author dealing with the spatial plan of Uherske Hradiste and the process of its acquisition, con-sistency with the other territorial analytical documents and especially the public areas with a predominance of non-paved areas, which are intended for public green (parks and wood-ed areas, for example location and architectural sites Sady and former Jewish cemetery). For individual areas, the author cares about whether it was filled with their main purpose: public green, including the type and quantity, and whether there are other acceptable ele-ments of small architecture and technical infrastructure.Ústav environmentální bezpečnost
Author Correction: A gate tunable transmon qubit in planar Ge
No full textCorrection to: Nature Communications https://doi.org/10.1038/s41467-024-50763-6, published online 30 July 2024 The original version of this Article omitted the following from the Acknowledgements: We acknowledge financial support from the Horizon Europe Framework Program of the European Commission through the European Innovation Council Pathfinder grant no. 101115315 (QuKiT). This has now been corrected in both the PDF and HTML versions of the Article
Windthrow Impact on the Operation and Managemet of TANAP
No full textCílem této bakalářské práce je obeznámit s událostí větrné kalamity, která dne 19. 11. 2004 poškodila Tatranský Národný Park (TANAP) v objemu 2 350 000 m3 dřevní hmoty. Autorka se zkoumá a hodnotí dopady této kalamity od roku 2004 2016. Problematika je nejprve obecně charakterizována a doplněna tabulkami. Převážná část práce je věnována napadení porostu v TANAPu lýkožroutem smrkovým (Ips typographus L.). Také zdůrazňuje význam jak zahraničních, tak i slovenských vědeckých studií a poznatků k tomuto tématu. Pro doplnění textové části je zpracována kapitola obsahující vlastní fotografie a mapy kalamitních oblastí, které autorka vytvořila na základě osobní návštěvy zkoumané oblasti.The main scope of this Bachelor thesis is to introduce the devastating outcome of a wind-storm that damaged the "Tatra national park" on 19. 11. 2004 in the volume of 2.35 million cubic meters of woods. The author of the thesis examines and assesses the impact of the calamity since 2004 till 2016. The first part is dedicated to general characteristics of the TANAP´s issue; it describes the status of the problem using applied tables. The main part is devoted to the attack of bark beetle (Ips typographus L.) on the woods and flora. The thesis includes and emphasis also on the importance of foreign as well as Slovak scientific studies and knowledge acquired, considering the topic. To complement the text parts, there is a chapter containing own photos and self-created maps of the examined area, which the author has visited personally.Ústav environmentální bezpečnost
Transport in silicon-germanium heterostructures
No full textThe work presented here describes the electrical characterization of n- and p-type strained silicon-germanium systems. Theories of quantum transport m low magnetic fields at low temperature are discussed m terms of weak-localization: the traditional theory is shown not to account for the dephasing in a 2-dimensional hole gas behaving in a metallic manner and emergent alternative theories, while promising, require refinement. The mobility as a function of sheet density is measured in a p-type pseudomorphic Si_0_._5Ge_0_._5 across the temperature range 350mK-282K; it is shown that calculations of the mobility based on semi-classical scattering mechanisms fail below 10K where quantum transport effects become relevant. A room temperature Hall scattering factor has been extracted. A new functional form has been presented to fit the resistivity as a function of temperature, below 20K: traditional theories of screening and weak localization appear not to be applicable. It is also demonstrated that simple protection circuitry is essential if commercial-scale devices are to be meaningfully investigated. Mobility spectrum analysis is performed on an n-type strained-silicon device. Established analysis methods are discussed and a new method is presented based on the Bryan's Algorithm approach to maximum entropy. The breakdown of the QHE is also investigated: the critical current density compares well to that predicted by an existing theory. Finally, devices in which both electron and hole gases can be induced are investigated. However, it is shown that the two cannier species never co-exist. Design rules are presented which may allow more successful structures to be created. Results are presented which demonstrate the success and the utility of implanted contacts which selectively reach different regions of the structure. (author)SIGLEAvailable from British Library Document Supply Centre- DSC:DXN054677 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Engineering of the spin on dopant process on silicon on insulator substrate
No full textWe report on a systematic analysis of phosphorus diffusion in silicon on insulator thin film via spin-on-dopant process (SOD). This method is used to provide an impurity source for semiconductor junction fabrication. The dopant is first spread into the substrate via SOD and then diffused by a rapid thermal annealing process. The dopant concentration and electron mobility were characterized at room and low temperature by four-probe and Hall bar electrical measurements. Time-of-flight-secondary ion mass spectroscopy was performed to estimate the diffusion profile of phosphorus for different annealing treatments. We find that a high phosphorous concentration (greater than 1020 atoms cm-3) with a limited diffusion of other chemical species and allowing to tune the electrical properties via annealing at high temperature for short time. The ease of implementation of the process, the low cost of the technique, the possibility to dope selectively and the uniform doping manufactured with statistical process control show that the methodology applied is very promising as an alternative to the conventional doping methods for the implementation of optoelectronic devices. QCD/Scappucci La
Research data for publication 'Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors'
No full textResearch Data for publication 'Strong charge-photon coupling in planar germanium enabled by granular aluminium superinductors'We acknowledge Franco De Palma, Mahya Khorramshahi, Fabian Oppliger, Thomas Reisinger, Pasquale Scarlino and Xiao Xue for helpful discussions. We thank Simon Robson for proofreading the manuscript. This research was supported by the Scientific Service Units of ISTA through resources provided by the MIBA Machine Shop and the Nanofabrication facility. This research and related results were made possible with the support of the NOMIS Foundation and the HORIZON-RIA 101069515 project. This research was funded in whole or in part by the Austrian Science Fund (FWF) DOI:10.55776/P32235, DOI:10.55776/I5060 and DOI:10.55776/P36507. For Open Access purposes, the author has applied a CC BY public copyright license to any author accepted manuscript version arising from this submission. M.J. acknowledges funding from FellowQUTE 2024-01. I.M.P. acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG – German Research Foundation) under project number 450396347 (GeHoldeQED). ICN2 acknowledges funding from Generalitat de Catalunya 2021SGR00457. We acknowledge support from CSIC Interdisciplinary Thematic Platform (PTI+) on Quantum Technologies (PTI-QTEP+). This research work has been funded by the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC's Quantum Technologies Platform (QTEP). ICN2 is supported by the Severo Ochoa program from Spanish MCIN/AEI (Grant No.: CEX2021-001214-S) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program. AGM has received funding from Grant RYC2021-033479-I funded by MCIN/AEI/10.13039/501100011033 and by European Union NextGenerationEU/PRTR. M.B. acknowledges support from SUR Generalitat de Catalunya and the EU Social Fund; project ref. 2020 FI 00103. The authors acknowledge the use of instrumentation and the technical advice provided by the Joint Electron Microscopy Center at ALBA (JEMCA). ICN2 acknowledges funding from Grant IU16-014206 (METCAM-FIB) funded by the European Union through the European Regional Development Fund (ERDF), with the support of the Ministry of Research and Universities, Generalitat de Catalunya. ICN2 is a founding member of e-DREAM.With funding from the Spanish government through the "Severo Ochoa Centre of Excelence" accreditation (CEX2021-001214-S)Peer reviewe
Mid-Infrared Intersubband Absorption in p-Ge/SiGe Quantum Wells Grown on Si
No full textIntersubband absorption from p-Ge quantum wells grown on Si is demonstrated. The absorption can be tuned by adjusting the quantum well thickness. FTIR transmission measurements on as-grown wafers show broad absorption at mid-infrared wavelengths
