TY - GEN
A1 - Weißhaupt, David
A1 - Sürgers, Christoph
A1 - Bloos, Dominik
A1 - Funk, Hannes Simon
A1 - Oehme, Michael
A1 - Fischer, Gerda
A1 - Schubert, Markus Andreas
A1 - Wenger, Christian
A1 - van Slageren, Joris
A1 - Fischer, Inga Anita
A1 - Schulze, Jörg
T1 - Lateral Mn5Ge3 spin-valve in contact with a high-mobility Ge two-dimensional hole gas
T2 - Semiconductor Science and Technology
N2 - Abstract
Ge two-dimensional hole gases (2DHG) in strained modulation-doped quantum-wells represent a promising material platform for future spintronic applications due to their excellent spin transport properties and the theoretical possibility of efficient spin manipulation. Due to the continuous development of epitaxial growth recipes extreme high hole mobilities and low effective masses can be achieved, promising an efficient spin transport. Furthermore, the Ge 2DHG can be integrated in the well-established industrial complementary metal-oxide-semiconductor (CMOS) devices technology. However, efficient electrical spin injection into a Ge 2DHG—an essential prerequisite for the realization of spintronic devices—has not yet been demonstrated. In this work, we report the fabrication and low-temperature magnetoresistance (MR) measurements of a laterally structured Mn5Ge3/Ge 2DHG/ Mn5Ge3 device. The ferromagnetic Mn5Ge3 contacts are grown directly into the Ge quantum well by means of an interdiffusion process with a spacing of approximately 130 nm, forming a direct electrical contact between the ferromagnetic metal and the Ge 2DHG. Here, we report for the first time a clear MR signal for temperatures below 13 K possibly arising from successful spin injection into the high mobility Ge 2DHG. The results represent a step forward toward the realization of CMOS compatible spintronic devices based on a 2DHG.
KW - two-dimensional hole gas
Y1 - 2024
U6 - https://doi.org/10.1088/1361-6641/ad8d06
SN - 0268-1242
VL - 39
IS - 12
SP - 1
EP - 10
PB - IOP Publishing
ER -
TY - GEN
A1 - Hayat, Ahsan
A1 - Ratzke, Markus
A1 - Alvarado Chavarin, Carlos
A1 - Zöllner, Marvin Hartwig
A1 - Corley-Wiciak, Agnieszka Anna
A1 - Schubert, Markus Andreas
A1 - Wenger, Christian
A1 - Fischer, Inga Anita
T1 - Structural and morphological properties of CeO2 films deposited by radio frequency magnetron sputtering for back-end-of-line integration
T2 - Thin Solid Films
Y1 - 2024
U6 - https://doi.org/10.1016/j.tsf.2024.140547
SN - 0040-6090
VL - 807
ER -
TY - GEN
A1 - Oleynik, Paul
A1 - Berkmann, Fritz
A1 - Reiter, Sebastian
A1 - Schlipf, Jon
A1 - Ratzke, Markus
A1 - Yamamoto, Yuji
A1 - Fischer, Inga Anita
T1 - Strong Optical Coupling of Lattice Resonances in a Top-down Fabricated Hybrid Metal–Dielectric Al/Si/Ge Metasurface
T2 - Nano Letters
N2 - Optical metasurfaces enable the manipulation of the light–matter interaction in ultrathin layers. Compared with their metal or dielectric counterparts, hybrid metasurfaces resulting from the combination of dielectric and metallic nanostructures can offer increased possibilities for interactions between modes present in the system. Here, we investigate the interaction between lattice resonances in a hybrid metal–dielectric metasurface obtained from a single-step nanofabrication process. Finite-difference time domain simulations show the avoided crossing of the modes appearing in the wavelength-dependent absorptance inside the Ge upon variations in a selected geometry parameter as evidence for strong optical coupling. We find good agreement between the measured and simulated absorptance and reflectance spectra. Our metasurface design can be easily incorporated into a top-down optoelectronic device fabrication process with possible applications ranging from on-chip spectroscopy to sensing.
KW - metamaterials
KW - semiconductors
KW - hybridization
KW - optoelectronics
Y1 - 2024
U6 - https://doi.org/10.1021/acs.nanolett.3c05050
SN - 1530-6984
SN - 1530-6992
VL - 24
IS - 10
SP - 3142
EP - 3149
ER -
TY - GEN
A1 - Kosto, Yuliia
A1 - Tschammer, Rudi
A1 - Morales, Carlos
A1 - Henkel, Karsten
A1 - Flege, Jan Ingo
A1 - Ratzke, Markus
A1 - Fischer, Inga Anita
A1 - Costina, Ioan
A1 - Alvarado Chavarin, Carlos
A1 - Wenger, Christian
T1 - Rational design and development of room temperature hydrogen sensors compatible with CMOS technology: a necessary step for the coming renewable hydrogen economy
T2 - Proceedings of iCampus Conference Cottbus 2024
N2 - The transition towards a new, renewable energy system based on green energy vectors, such as hydrogen, requires not only direct energy conversion and storage systems, but also the development of auxiliary components, such as highly sensitive hydrogen gas sensors integrated into mass devices that operate at ambient conditions. Despite the recent advances in nanostructured metal oxide thin films in terms of simple fabrication processes and compatibility with integrated circuits, high sensitivity, and short response/recovery times usually require the use of expensive noble metals or elevated tem-peratures (>250 ºC), which results in high power consumption and poor long-term stability. This article presents the first steps of the work on developing a novel resistive hydrogen gas sensor based on ultrathin cerium oxide films, compatible with complementary metal oxide semiconductor technology and capable of operating at room temperature. Here, we show a multidisciplinary bottom-up approach combining different work areas for the sensor development, such as sensor architecture, sensing mechanism and deposition strategy of the active layer, electrical contact design depending on the desired electrical output, and fast testing under controlled environments.
KW - gas sensors
KW - micro-structering
KW - atomic layer deposition
KW - sensor platform
Y1 - 2024
SN - 978-3-910600-00-3
U6 - https://doi.org/10.5162/iCCC2024/P21
SP - 182
EP - 185
PB - AMA Service GmbH
CY - Wunstorf
ER -
TY - GEN
A1 - Eisenhauer, Nico
A1 - Frank, Karin
A1 - Weigelt, Alexandra
A1 - Bartkowski, Bartosz
A1 - Beugnon, Rémy
A1 - Liebal, Katja
A1 - Mahecha, Miguel
A1 - Quaas, Martin
A1 - Al‐Halbouni, Djamil
A1 - Bastos, Ana
A1 - Bohn, Friedrich J.
A1 - Brito, Mariana Madruga de
A1 - Denzler, Joachim
A1 - Feilhauer, Hannes
A1 - Fischer, Rico
A1 - Fritsche, Immo
A1 - Guimaraes‐Steinicke, Claudia
A1 - Hänsel, Martin
A1 - Haun, Daniel B. M.
A1 - Herrmann, Hartmut
A1 - Huth, Andreas
A1 - Kalesse‐Los, Heike
A1 - Koetter, Michael
A1 - Kolleck, Nina
A1 - Krause, Melanie
A1 - Kretschmer, Marlene
A1 - Leitão, Pedro J.
A1 - Masson, Torsten
A1 - Mora, Karin
A1 - Müller, Birgit
A1 - Peng, Jian
A1 - Pöhlker, Mira L.
A1 - Ratzke, Leonie
A1 - Reichstein, Markus
A1 - Richter, Solveig
A1 - Rüger, Nadja
A1 - Sánchez‐Parra, Beatriz
A1 - Shadaydeh, Maha
A1 - Sippel, Sebastian
A1 - Tegen, Ina
A1 - Thrän, Daniela
A1 - Umlauft, Josefine
A1 - Wendisch, Manfred
A1 - Wolf, Kevin
A1 - Wirth, Christian
A1 - Zacher, Hannes
A1 - Zaehle, Sönke
A1 - Quaas, Johannes
T1 - A belowground perspective on the nexus between biodiversity change, climate change, and human well‐being
T2 - Journal of Sustainable Agriculture and Environment
N2 - Soil is central to the complex interplay among biodiversity, climate, and society. This paper examines the interconnectedness of soil biodiversity, climate change, and societal impacts, emphasizing the urgent need for integrated solutions. Human‐induced biodiversity loss and climate change intensify environmental degradation, threatening human well‐being. Soils, rich in biodiversity and vital for ecosystem function regulation, are highly vulnerable to these pressures, affecting nutrient cycling, soil fertility, and resilience. Soil also crucially regulates climate, influencing energy, water cycles, and carbon storage. Yet, climate change poses significant challenges to soil health and carbon dynamics, amplifying global warming. Integrated approaches are essential, including sustainable land management, policy interventions, technological innovations, and societal engagement. Practices like agroforestry and organic farming improve soil health and mitigate climate impacts. Effective policies and governance are crucial for promoting sustainable practices and soil conservation. Recent technologies aid in monitoring soil biodiversity and implementing sustainable land management. Societal engagement, through education and collective action, is vital for environmental stewardship. By prioritizing interdisciplinary research and addressing key frontiers, scientists can advance understanding of the soil biodiversity–climate change–society nexus, informing strategies for environmental sustainability and social equity.
Y1 - 2024
U6 - https://doi.org/10.1002/sae2.12108
SN - 2767-035X
VL - 3
IS - 2
PB - Wiley
ER -
TY - GEN
A1 - Reiter, Sebastian
A1 - Han, Weijia
A1 - Mai, Christian
A1 - Spirito, Davide
A1 - Jose, Josmy
A1 - Zöllner, Marvin Hartwig
A1 - Fursenko, Oksana
A1 - Schubert, Markus Andreas
A1 - Stemmler, Ivo
A1 - Wenger, Christian
A1 - Fischer, Inga Anita
T1 - Titanium Nitride Plasmonic Nanohole Arrays for CMOS-compatible integrated refractive index sensing: influence of layer thickness on optical properties
T2 - Plasmonics
Y1 - 2023
U6 - https://doi.org/10.1007/s11468-023-01810-3
SN - 1557-1963
SP - 1
EP - 13
ER -
TY - GEN
A1 - Pieper, Dawid
A1 - Behnke, Eva‐Maria
A1 - Dumke, Rieke
A1 - Kehr‐Fuckel, Christel
A1 - Radow, Carolin
A1 - Schulze, Nils
A1 - Follmann, Markus
A1 - Schaefer, Corinna
A1 - Prill, Robert
A1 - Kopkow, Christian
A1 - Bahns, Carolin
A1 - Choi, Kyung‐Eun (Anna)
A1 - Fischer, Lena
T1 - Awareness of adapting clinical practice guidelines to a local context
T2 - Clinical and public health guidelines
N2 - Background
Guideline recommendations are often not implemented in practice. This can be attributed to factors such as patient preferences and characteristics, structural conditions, personnel or other resources, as well as cultural or ethical aspects. Adaptations to the local context (e.g., regional or hospital) result in so-called locally adapted guidelines (LAGL), which could improve implementation. We aimed to assess the awareness of LAGL among guideline developers in Germany.
Methods
An online survey was conducted via LimeSurvey in May 2024. The questionnaire, designed based on literature and expert opinions, consisted of 23 items, predominantly with dichotomous response options. Recruitment was conducted via email. Direct contact addresses were identified using the German guideline registry (n = 397). Additionally, a mailing list distribution was conducted through the guidelines working group of the German Network for Evidence-Based Medicine (n = 316). Only fully completed questionnaires were included in the analysis. Data cleaning and descriptive analysis were performed using Excel.
Results
A total of 63 questionnaires were fully completed. The most represented groups were physicians (65%) and methodologists (24%), most frequently in coordination (76%) or as group members (62%). The most judicious reasons for developing a LAGL were differences in patient populations (48%), currency of recommendations (46%), and patient values and preferences (44%). The most commonly cited likely reasons for developing a LAGL were economic considerations (32%), differences in patient populations (30%), and currency of recommendations (30%). Many respondents (59%) were aware of the possibility of adapting existing guidelines to the local context. Among these, approximately half (49%) had already locally adapted a guideline, with 75% using an adaptation framework.
Discussion
LAGLs are known among guideline developers in Germany and are generally developed using adaptation frameworks. Potential reasons for preparing LAGLs are diverse, with some discrepancies between perceived valid and likely reasons.
Highlights
Over half (59%) of surveyed clinical practice guideline (CPG) developers in Germany were aware of the possibility of adapting CPGs to local contexts, and nearly half of them had practical experience doing so.
Although several adaptation frameworks exist, only 44% of experienced adaptors were familiar with them, and among users, many found them only partly helpful.
Differences in patient populations, outdated recommendations, and patient values were rated as the most valid reasons for local CPG adaptation, while economic factors were seen as the most likely driver in practice.
Despite existing awareness, guideline adaptation to local settings remains underutilized and lacks structured implementation, highlighting the need for clearer definitions, better resources, and more practical examples.
KW - Leitlinien
Y1 - 2025
U6 - https://doi.org/10.1002/gin2.70025
SN - 2836-3973
VL - 2
IS - 3
SP - 1
EP - 7
PB - Wiley
CY - Hobken, New Jersey
ER -
TY - GEN
A1 - Reiter, Sebastian
A1 - Ratzke, Markus
A1 - Nitsch, Paul-Gregor
A1 - Mai, Christian
A1 - Spirito, Davide
A1 - Corley-Wiciak, Agnieszka Anna
A1 - Wenger, Christian
A1 - Fischer, Inga A.
T1 - Optical response of titanium nitride plasmonic nanohole arrays : impact of square and hexagonal array geometry, pitch, and nanohole diameter
T2 - Plasmonics
N2 - Plasmonic nanohole arrays (NHAs) exhibit extraordinary optical transmission (EOT) evoked by resonant excitation of surface plasmons at an excitation wavelength, which is highly sensitive to changes in refractive index in the surrounding dielectric. This can enable the use of plasmonic NHAs in on-chip refractive index sensors. Such sensors can be realized on the cost-effective silicon platform by the integration of a plasmonic NHA and a Ge photodetector, provided that complementary metal–oxide–semiconductor (CMOS)-compatible materials are used for their fabrication. Titanium nitride (TiN) as a biocompatible and CMOS-compatible plasmonic transition metal nitride is well-suited for integration on the silicon platform; however, the comparatively large losses within the material require geometry optimization strategies in order to improve the optical properties of TiN NHAs for sensing. In this work, we investigated different TiN NHA geometries both in experiment and simulation. We extensively characterized square and hexagonal arrays with varying pitches and nanohole diameters and provide a detailed comparison of their optical properties. We also discuss characterization results for surface refractive index changes imposed by depositing a thin Al2O3 layer on top of the NHAs. While we do not observe a clear advantage of hexagonal arrays compared to square arrays for sensing, our results highlight the importance of geometry optimization for TiN NHAs integrated with devices.
KW - Plasmonic nanohole array
KW - Titanium nitride
KW - Hexagonal array
KW - Square array
KW - Nanohole diameters
Y1 - 2025
UR - https://link.springer.com/article/10.1007/s11468-025-02934-4
U6 - https://doi.org/10.1007/s11468-025-02934-4
VL - 20
SP - 8825
EP - 8834
PB - Springer
CY - New York, NY
ER -