@misc{ZoellnerAdrianoWiethegeretal., author = {Z{\"o}llner, Christian and Adriano, Christian M. and Wietheger, Simon and Lambers, Leen and Giese, Holger}, title = {Tool support for the teaching of state-based behavior modeling}, series = {MODELS '22: Proceedings of the 25th International Conference on Model Driven Engineering Languages and Systems: Companion Proceedings}, journal = {MODELS '22: Proceedings of the 25th International Conference on Model Driven Engineering Languages and Systems: Companion Proceedings}, editor = {K{\"u}hn, Thomas and Sousa, Vasco}, publisher = {Association for Computing Machinery}, address = {New York, NY, United States}, isbn = {978-1-4503-9467-3}, doi = {10.1145/3550356.3556501}, pages = {87 -- 94}, abstract = {Modeling tools are commonly adopted in classrooms. However, complex state-based behavioral models still pose a challenge for students to understand and validate, mostly because of the intricate semantics of these models. We investigated this challenge and developed dedicated tool support in the form of a validation framework based on the YAKINDU Statechart Tools. Our validation framework simulates environments that interact with the code generated from statecharts as a means to animate various open-ended scenarios and predefined test cases that challenge the students' models. This enables short and user-friendly feedback cycles, which lowers the barrier for students to learn state-based behavioral models. We designed the validation framework to be extensible and made it available as an open source project together with two example environments and complete teaching materials. We report on our experiences in two undergraduate modeling courses (approx. 100 students each). Our results are promising in the sense that we detected positive effects of tool adoption and a surprising lack thereof, which we discuss w.r.t. lessons learned and future work.}, language = {en} } @misc{ReiterHanMaietal., author = {Reiter, Sebastian and Han, Weijia and Mai, Christian and Spirito, Davide and Jose, Josmy and Z{\"o}llner, Marvin Hartwig and Fursenko, Oksana and Schubert, Markus Andreas and Stemmler, Ivo and Wenger, Christian and Fischer, Inga Anita}, title = {Titanium Nitride Plasmonic Nanohole Arrays for CMOS-Compatible Integrated Refractive Index Sensing: Influence of Layer Thickness on Optical Properties}, series = {Plasmonics}, journal = {Plasmonics}, issn = {1557-1963}, doi = {10.1007/s11468-023-01810-3}, pages = {1 -- 13}, language = {en} } @misc{FoersterSchenkZollneretal., author = {F{\"o}rster, Stefan and Schenk, Sebastian and Zollner, Eva Maria and Krahn, Oliver and Chiang, Cheng-Tien and Schumann, Florian O. and Bayat, Alireza and Schindler, Karl-Michael and Trautmann, Martin and Hammer, Ren{\´e} and Meinel, Klaus and Adeagbo, Waheed A. and Hergert, Wolfram and Flege, Jan Ingo and Falta, Jens and Ellguth, Martin and Tusche, Christian and DeBoissieu, Marc and Muntwiler, Matthias and Gerber, Thomas and Widdra, Wolf}, title = {Quasicrystals and their Approximants in 2D Ternary Oxides}, series = {Physia Status Solidi B}, volume = {257}, journal = {Physia Status Solidi B}, number = {7}, issn = {0370-1972}, doi = {10.1002/pssb.201900624}, pages = {11}, abstract = {2D oxide quasicrystals (OQCs) are recently discovered aperiodic, but well-ordered oxide interfaces. In this topical review, an introduction to these new thin-film systems is given. The concept of quasicrystals and their approximants is explained for BaTiO3 and SrTiO3 derived OQCs and related periodic structures in these 2D oxides. In situ microscopy unravels the high-temperature formation process of OQCs on Pt(111). The dodecagonal structure is discussed regarding tiling statistics and tiling decoration based on the results of atomically resolved scanning tunneling microscopy and various diffraction techniques. In addition, angle-resolved ultraviolet photoemission spectroscopy and X-ray photoelectron spectroscopy results prove a metallic character of the 2D oxide.}, language = {en} } @misc{NiuZoellnerSchroederetal., author = {Niu, Gang and Z{\"o}llner, Marvin Hartwig and Schr{\"o}der, Thomas and Sch{\"a}fer, Andreas and Jhang, Jin-Hao and Zielasek, Volkmar and B{\"a}umer, Marcus and Wilkens, Henrik and Wollschl{\"a}ger, Joachim and Olbrich, Reinhard and Lammers, Christian and Reichling, Michael}, title = {Controlling the physics and chemistry of binary and ternary praseodymium and cerium oxide systems}, series = {Physical Chemistry Chemical Physics}, volume = {17}, journal = {Physical Chemistry Chemical Physics}, number = {38}, issn = {1463-9084}, doi = {10.1039/C5CP02283E}, pages = {24513 -- 24540}, language = {en} } @misc{MahmoodinezhadMoralesNaumannetal., author = {Mahmoodinezhad, Ali and Morales, Carlos and Naumann, Franziska and Plate, Paul and Meyer, Robert and Janowitz, Christoph and Henkel, Karsten and Kot, Małgorzata and Z{\"o}llner, Marvin Hartwig and Wenger, Christian and Flege, Jan Ingo}, title = {Low-temperature atomic layer deposition of indium oxide thin films using trimethylindium and oxygen plasma}, series = {Journal of Vacuum Science and Technology A}, volume = {39}, journal = {Journal of Vacuum Science and Technology A}, number = {6}, issn = {0734-2101}, doi = {10.1116/6.0001375}, abstract = {Indium oxide (InxOy) thin films were deposited by plasma-enhanced atomic layer deposition (PEALD) using trimethylindium and oxygen plasma in a low-temperature range of 80-200 °C. The optical properties, chemical composition, crystallographic structure, and electrical characteristics of these layers were investigated by spectroscopic ellipsometry (SE), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), as well as current-voltage and capacitance-voltage measurements. The SE results yielded a nearly constant growth rate of 0.56 {\AA} per cycle and a thickness inhomogeneity of ≤1.2\% across 4-in. substrates in the temperature range of 100-150 °C. The refractive index (at 632.8 nm) was found to be 2.07 for the films deposited at 150 °C. The PEALD-InxOy layers exhibit a direct (3.3 ± 0.2 eV) and an indirect (2.8 ± 0.1 eV) bandgap with an uptrend for both with increasing substrate temperature. Based on XPS characterization, all InxOy samples are free of carbon impurities and show a temperature-dependent off-stoichiometry indicating oxygen vacancies. XRD diffraction patterns demonstrate an onset of crystallization at 150 °C. Consistent with the optical, XPS, and XRD data, the films deposited at ≥150 °C possess higher electrical conductivity. Our findings prove that a low-temperature PEALD process of InxOy is feasible and promising for a high-quality thin-film deposition without chemical impurities on thermally fragile substrates.}, language = {en} } @misc{KuschelDieckWilkensetal., author = {Kuschel, Olga and Dieck, Florian and Wilkens, Henrik and Gevers, Sebastian and Rodewald, Jari and Otte, Christian and Z{\"o}llner, Marvin Hartwig and Niu, Gang and Schr{\"o}der, Thomas and Wollschl{\"a}ger, Joachim}, title = {Plasma Enhanced Complete Oxidtation of Ultrathin Epitaxial Praseodymia Films on Si(111)}, series = {Materials}, volume = {8}, journal = {Materials}, number = {9}, issn = {1996-1944}, doi = {10.3390/ma8095312}, pages = {6379 -- 6390}, language = {en} } @misc{JanowitzMahmoodinezhadKotetal., author = {Janowitz, Christoph and Mahmoodinezhad, Ali and Kot, Małgorzata and Morales, Carlos and Naumann, Franziska and Plate, Paul and Z{\"o}llner, Marvin Hartwig and B{\"a}rwolf, Florian and Stolarek, David and Wenger, Christian and Henkel, Karsten and Flege, Jan Ingo}, title = {Toward controlling the Al2O3/ZnO interface properties by in situ ALD preparation}, series = {Dalton Transactions}, volume = {51}, journal = {Dalton Transactions}, issn = {1477-9234}, doi = {10.1039/D1DT04008A}, pages = {9291 -- 9301}, abstract = {An Al2O3/ZnO heterojunction was grown on a Si single crystal substrate by subsequent thermal and plasma-assisted atomic layer deposition (ALD) in situ. The band offsets of the heterointerface were then studied by consecutive removal of the layers by argon sputtering, followed by in situ X-ray photoelectron spectroscopy. The valence band maximum and conduction band minimum of Al2O3 are found to be 1.1 eV below and 2.3 eV above those of ZnO, resulting in a type-I staggered heterojunction. An apparent reduction of ZnO to elemental Zn in the interface region was detected in the Zn 2p core level and Zn L3MM Auger spectra. This suggests an interface formation different from previous models. The reduction of ZnO to Zn in the interface region accompanied by the creation of oxygen vacancies in ZnO results in an upward band bending at the interface. Therefore, this study suggests that interfacial properties such as the band bending as well as the valence and conduction band offsets should be in situ controllable to a certain extent by careful selection of the process parameters.}, language = {en} } @misc{ZoellnerRichardChahineetal., author = {Z{\"o}llner, Marvin Hartwig and Richard, Marie-Ingrid and Chahine, Gilbert A. and Zaumseil, Peter and Reich, Christian and Capellini, Giovanni and Montalenti, Francesco and Marzegalli, Anna and Xie, Ya-Hong and Sch{\"u}lli, Tobias U. and H{\"a}berlen, Maik and Storck, Peter and Schroeder, Thomas}, title = {Imaging structure and composition homogeneity of 300 mm SiGe virtual substrates for advanced CMOS applications by scanning X-ray diffraction microscopy}, series = {ACS Applied Materials and Interfaces}, volume = {7}, journal = {ACS Applied Materials and Interfaces}, number = {17}, issn = {1944-8252}, doi = {10.1021/am508968b}, pages = {9031 -- 9037}, language = {en} }