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DDC: 620 × Subject: XPS ×

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    Auger- and X-ray Photoelectron Spectroscopy at Metallic Li Material: Chemical Shifts Related to Sample Preparation, Gas Atmosphere, and Ion and Electron Beam Effects
    (Basel : MDPI, 2022) Oswald, Steffen
    Li-based batteries are a key element in reaching a sustainable energy economy in the near future. The understanding of the very complex electrochemical processes is necessary for the optimization of their performance. X-ray photoelectron spectroscopy (XPS) is an accepted method used to improve understanding around the chemical processes at the electrode surfaces. Nevertheless, its application is limited because the surfaces under investigation are mostly rough and inhomogeneous. Local elemental analysis, such as Auger electron spectroscopy (AES), could assist XPS to gain more insight into the chemical processes at the surfaces. In this paper, some challenges in using electron spectroscopy are discussed, such as binding energy (BE) referencing for the quantitative study of chemical shifts, gas atmospheric influences, or beam damage (including both AE and XP spectroscopy). Carefully prepared and surface-modified metallic lithium material is used as model surface, considering that Li is the key element for most battery applications.
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    Evaluation of surface cleaning procedures for CTGS substrates for SAW technology with XPS
    (Basel : MDPI, 2017) Brachmann, Erik; Seifert, Marietta; Oswald, Steffen; Menzel, Siegfried B.; Gemming, Thomas
    A highly efficient and reproducible cleaning procedure of piezoelectric substrates is essential in surface acoustic waves (SAW) technology to fabricate high-quality SAW devices, especially for new applications such SAW sensors wherein new materials for piezoelectric substrates and interdigital transducers are used. Therefore, the development and critical evaluation of cleaning procedures for each material system that is under consideration becomes crucial. Contaminants like particles or the presence of organic/inorganic material on the substrate can dramatically influence and alter the properties of the thin film substrate composite, such as wettability, film adhesion, film texture, and so on. In this article, focus is given to different cleaning processes like SC-1 and SC-2, UV-ozone treatment, as well as cleaning by first-contact polymer Opticlean, which are applied for removal of contaminants from the piezoelectric substrate Ca 3 TaGa 3 Si 2 O 14 . By means of X-ray photoelectron spectroscopy, the presence of the most critical contaminants such as carbon, sodium, and iron removed through different cleaning procedures were studied and significant differences were observed between the outcomes of these procedures. Based on these results, a two-step cleaning process, combining SC-1 at a reduced temperature at 30 ∘ C instead of 80 ∘ C and a subsequent UV-ozone cleaning directly prior to deposition of the metallization, is suggested to achieve the lowest residual contamination level.
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    Ausbau des Kompetenzzentrums Dünnschicht und Nanotechnologie für Photovoltaik Berlin, Teilvorhaben 6: Analytik
    (Hannover : Technische Informationsbibliothek (TIB), 2014) Klingsporn, Max; Costina,, Ioan
    Derzeitiger Stand von Wissenschaft und Technik Die Photovoltaiklandschaft in Deutschland ist von der Wafer-Technologie dominiert. Im Bereich Dünnschicht-PV gibt es zahlreiche vielversprechende Entwicklungspotentiale, für die jedoch auch die geeigneten Depositions-, Analyse- und Simulationsverfahren zur Verfügung stehen müssen. Zielsetzung Ziel des Teilvorhabens war der Aufbau eines instituts- und standortübergreifenden Analysenetzwerks für Dünnschichtsolarzellen, um, durch die Kombination einer Vielzahl von in der Halbleiterindustrie etablierter Methoden mit neuentwickelten Messverfahren und begleitenden theoretischen Simulationen, neue Ansätze und Wege zur Wirkungsgradsteigerung von Silizium und CIS basierten Dünnschichtsolarzellen zu entwickeln. Ergebnis Die bisher nur in der Mikroelektronik genutzten Analysemöglichkeiten wurden hinsichtlich Probenpräparation und Messbedingungen auf die Untersuchung von Solarzellen angepasst. Dafür wurden spezielle Probenhalter, Eichproben Messkonzepte und Messrezepte angefertigt bzw. entwickelt. Anwendungsmöglichkeiten Die gewonnenen Erkenntnisse tragen zur Erweiterung der Kompetenzen auf dem Gebiet der Dünnschichtsolarzellenforschung im IHP bei und haben zur Entstehung einer permanenten Plattform für künftige Charakterisierungen auf diesem Anwendungsgebiet geführt.