TY - JOUR
AB - The defect-electronic properties of {112} microfaceted surfaces of epitaxially grown CuInSe2 thin films are investigated by scanning tunneling spectroscopy and photoelectron spectroscopy techniques after various surface treatments. The intrinsic CuInSe2 surface is found to be largely passivated in terms of electronic defect levels in the band-gap region. However, surface oxidation leads to an overall high density of defect levels in conjunction with a considerable net surface dipole, which persists even after oxide removal. Yet, a subsequent annealing under vacuum restores the initial condition. Such oxidation/reduction cycles are reversible for many times providing robust control of the surface and interface properties in these materials. Based on ab initio simulations, a mechanism where oxygen dissociatively adsorbs and subsequently diffuses to a subsurface site is proposed as the initial step of the observed dipole formation. Our results emphasize the relevance of oxidation-induced dipole effects at the thin film surface and provide a comprehensive understanding toward passivation strategies of these surfaces.
AU - Elizabeth, Amala
AU - Sahoo, Sudhir K.
AU - Lockhorn, David
AU - Timmer, Alexander
AU - Aghdassi, Nabi
AU - Zacharias, Helmut
AU - Kühne, Thomas
AU - Siebentritt, Susanne
AU - Mirhosseini, Hossein
AU - Mönig, Harry
ID - 19844
JF - Phys. Rev. Materials
TI - Oxidation/reduction cycles and their reversible effect on the dipole formation at CuInSe2 surfaces
VL - 4
ER -
TY - JOUR
AB - Photovoltaics is one of the most promising and fastest-growing renewable energy technologies. Although the price-performance ratio of solar cells has improved significantly over recent years{,} further systematic investigations are needed to achieve higher performance and lower cost for future solar cells. In conjunction with experiments{,} computer simulations are powerful tools to investigate the thermodynamics and kinetics of solar cells. Over the last few years{,} we have developed and employed advanced computational techniques to gain a better understanding of solar cells based on copper indium gallium selenide (Cu(In{,}Ga)Se2). Furthermore{,} we have utilized state-of-the-art data-driven science and machine learning for the development of photovoltaic materials. In this Perspective{,} we review our results along with a survey of the field.
AU - Mirhosseini, S. Hossein
AU - Kormath Madam Raghupathy, Ramya
AU - Sahoo, Sudhir K.
AU - Wiebeler, Hendrik
AU - Chugh, Manjusha
AU - Kühne, Thomas
ID - 21112
JF - Phys. Chem. Chem. Phys.
TI - In silico investigation of Cu(In,Ga)Se2-based solar cells
VL - 22
ER -
TY - JOUR
AB - Rechargeable aqueous Zn-ion energy storage devices are promising candidates for next-generation energy storage technologies. However, the lack of highly reversible Zn2+-storage anode materials with low potential windows remains a primary concern. Here, we report a two-dimensional polyarylimide covalent organic framework (PI-COF) anode with high-kinetics Zn2+-storage capability. The well-organized pore channels of PI-COF allow the high accessibility of the build-in redox-active carbonyl groups and efficient ion diffusion with a low energy barrier. The constructed PI-COF anode exhibits a specific capacity (332 C g–1 or 92 mAh g–1 at 0.7 A g–1), a high rate capability (79.8% at 7 A g–1), and a long cycle life (85% over 4000 cycles). In situ Raman investigation and first-principle calculations clarify the two-step Zn2+-storage mechanism, in which imide carbonyl groups reversibly form negatively charged enolates. Dendrite-free full Zn-ion devices are fabricated by coupling PI-COF anodes with MnO2 cathodes, delivering excellent energy densities (23.9 ∼ 66.5 Wh kg–1) and supercapacitor-level power densities (133 ∼ 4782 W kg–1). This study demonstrates the feasibility of covalent organic framework as Zn2+-storage anodes and shows a promising prospect for constructing reliable aqueous energy storage devices.
AU - Yu, Minghao
AU - Chandrasekhar, Naisa
AU - Kormath Madam Raghupathy, Ramya
AU - Ly, Khoa Hoang
AU - Zhang, Haozhe
AU - Dmitrieva, Evgenia
AU - Liang, Chaolun
AU - Lu, Xihong
AU - Kühne, Thomas
AU - Mirhosseini, S. Hossein
AU - Weidinger, Inez M.
AU - Feng, Xinliang
ID - 21240
IS - 46
JF - Journal of the American Chemical Society
SN - 0002-7863
TI - A High-Rate Two-Dimensional Polyarylimide Covalent Organic Framework Anode for Aqueous Zn-Ion Energy Storage Devices
VL - 142
ER -
TY - JOUR
AB - Lead halide perovskite semiconductors providing record efficiencies of solar cells have usually mixed compositions doped in A- and X-sites to enhance the phase stability. The cubic form of formamidinium (FA) lead iodide reveals excellent opto-electronic properties but transforms at room temperature (RT) into a hexagonal structure which does not effectively absorb visible light. This metastable form and the mechanism of its stabilization by Cs+ and Br− incorporation are poorly characterized and insufficiently understood. We report here the vibrational properties of cubic FAPbI3 investigated by DFT calculations on phonon frequencies and intensities, and micro-Raman spectroscopy. The effects of Cs+ and Br− partial substitution are discussed. We support our results with the study of FAPbBr3 which expands the identification of vibrational modes to the previously unpublished low frequency region (<500 cm−1). Our results show that the incorporation of Cs+ and Br− leads to the coupling of the displacement of the A-site components and weakens the bonds between FA+ and the PbX6 octahedra. We suggest that the enhancement of α-FAPbI3 stability can be a product of the release of tensile stresses in the Pb–X bond, which is reflected in a red-shift of the low frequency region of the Raman spectrum (<200 cm−1).
AU - Ibaceta-Jaña, Josefa
AU - Muydinov, Ruslan
AU - Rosado, Pamela
AU - Mirhosseini, Hossein
AU - Chugh, Manjusha
AU - Nazarenko, Olga
AU - Dirin, Dmitry N.
AU - Heinrich, Dirk
AU - Wagner, Markus R.
AU - Kühne, Thomas
AU - Szyszka, Bernd
AU - Kovalenko, Maksym V.
AU - Hoffmann, Axel
ID - 17374
JF - Phys. Chem. Chem. Phys.
TI - Vibrational dynamics in lead halide hybrid perovskites investigated by Raman spectroscopy
VL - 22
ER -
TY - JOUR
AB - The record conversion efficiency of thin-film solar cells based on Cu(In,Ga)Se2 (CIGS) absorbers has exceeded 23%. Such a high performance is currently only attainable by the incorporation of heavy alkali metals like Cs into the absorber through an alkali fluoride post-deposition treatment (PDT). As the effect of the incorporated heavy alkali metals is under discussion, we investigated the local composition and microstructure of high efficiency CIGS solar cells via various high-resolution techniques in a combinatory approach. An accumulation of Cs is clearly detected at the p-n junction along with variations in the local CIGS composition, showing the formation of a beneficial secondary phase with a laterally inhomogeneous distribution. Additionally, Cs accumulations were detected at grain boundaries with a random misorientation of the adjacent grains where a reduced Cu concentration and increased In and Se concentrations are detected. No accumulation was found at Σ3 twin boundaries as well as the grain interior. These experimental findings are in excellent agreement with complementary ab-initio calculations, demonstrating that the grain boundaries are passivated by the presence of Cs. Further, it is unlikely that Cs with its large ionic radius is incorporated into the CIGS grains where it would cause detrimental defects.
AU - Schöppe, Philipp
AU - Schönherr, Sven
AU - Chugh, Manjusha
AU - Mirhosseini, Hossein
AU - Jackson, Philip
AU - Wuerz, Roland
AU - Ritzer, Maurizio
AU - Johannes, Andreas
AU - Martínez-Criado, Gema
AU - Wisniewski, Wolfgang
AU - Schwarz, Torsten
AU - T. Plass, Christian
AU - Hafermann, Martin
AU - Kühne, Thomas
AU - S. Schnohr, Claudia
AU - Ronning, Carsten
ID - 17376
JF - Nano Energy
SN - 2211-2855
TI - Revealing the origin of the beneficial effect of cesium in highly efficient Cu(In,Ga)Se2 solar cells
VL - 71
ER -
TY - BOOK
AU - Tönsing, Johanna
ID - 32425
TI - Animalische Epistemologie: Tierwahrheiten bei Franz Kafka am Beispiel von "Ein Bericht für eine Akademie"
ER -
TY - JOUR
AB - AbstractElectroencephalographic (EEG) research indicates changes in adults’ low frequency bands of frontoparietal brain areas executing different balance tasks with increasing postural demands. However, this issue is unsolved for adolescents when performing the same balance task with increasing difficulty. Therefore, we examined the effects of a progressively increasing balance task difficulty on balance performance and brain activity in adolescents. Thirteen healthy adolescents aged 16–17 year performed tests in bipedal upright stance on a balance board with six progressively increasing levels of task difficulty. Postural sway and cortical activity were recorded simultaneously using a pressure sensitive measuring system and EEG. The power spectrum was analyzed for theta (4–7 Hz) and alpha-2 (10–12 Hz) frequency bands in pre-defined frontal, central, and parietal clusters of electrocortical sources. Repeated measures analysis of variance (rmANOVA) showed a significant main effect of task difficulty for postural sway (p < 0.001; d = 6.36). Concomitantly, the power spectrum changed in frontal, bilateral central, and bilateral parietal clusters. RmANOVAs revealed significant main effects of task difficulty for theta band power in the frontal (p < 0.001, d = 1.80) and both central clusters (left: p < 0.001, d = 1.49; right: p < 0.001, d = 1.42) as well as for alpha-2 band power in both parietal clusters (left: p < 0.001, d = 1.39; right: p < 0.001, d = 1.05) and in the central right cluster (p = 0.005, d = 0.92). Increases in theta band power (frontal, central) and decreases in alpha-2 power (central, parietal) with increasing balance task difficulty may reflect increased attentional processes and/or error monitoring as well as increased sensory information processing due to increasing postural demands. In general, our findings are mostly in agreement with studies conducted in adults. Similar to adult studies, our data with adolescents indicated the involvement of frontoparietal brain areas in the regulation of postural control. In addition, we detected that activity of selected brain areas (e.g., bilateral central) changed with increasing postural demands.
AU - Gebel, Arnd
AU - Lehmann, Tim
AU - Granacher, Urs
ID - 32442
IS - 5
JF - Experimental Brain Research
KW - General Neuroscience
SN - 0014-4819
TI - Balance task difficulty affects postural sway and cortical activity in healthy adolescents
VL - 238
ER -
TY - JOUR
AU - Aly, Kamal I.
AU - Sun, Jingjiang
AU - Kuckling, Dirk
AU - Younis, Osama
ID - 23855
JF - Journal of Polymer Research
SN - 1022-9760
TI - Polyester resins based on soybean oil: synthesis and characterization
VL - 27
ER -
TY - JOUR
AU - Li, Jie
AU - Ji, Chendong
AU - Lü, Baozhong
AU - Rodin, Maksim
AU - Paradies, Jan
AU - Yin, Meizhen
AU - Kuckling, Dirk
ID - 23852
IS - 33
JF - ACS Applied Materials & Interfaces
SN - 1944-8244
TI - Dually Crosslinked Supramolecular Hydrogel for Cancer Biomarker Sensing
VL - 12
ER -
TY - JOUR
AU - Hou, Peng
AU - Oechsle, Peter
AU - Kuckling, Dirk
AU - Paradies, Jan
ID - 23857
IS - 10
JF - Macromolecular Rapid Communications
SN - 1022-1336
TI - Palladium‐Catalyzed Polycondensation for the Synthesis of Poly(Aryl)Sulfides
VL - 41
ER -
TY - JOUR
AU - Berg, Patrik
AU - Obst, Franziska
AU - Simon, David
AU - Richter, Andreas
AU - Appelhans, Dietmar
AU - Kuckling, Dirk
ID - 23849
JF - European Journal of Organic Chemistry
SN - 1434-193X
TI - Novel Application of Polymer Networks Carrying Tertiary Amines as a Catalyst Inside Microflow Reactors Used for Knoevenagel Reactions
ER -
TY - JOUR
AU - Berg, Marie-Theres
AU - Mertens, Chiel
AU - Du Prez, Filip
AU - Kühne, Thomas D.
AU - Herberg, Artjom
AU - Kuckling, Dirk
ID - 23848
JF - RSC Advances
SN - 2046-2069
TI - Analysis of sequence-defined oligomers through Advanced Polymer Chromatography™ – mass spectrometry hyphenation
VL - 10
ER -
TY - JOUR
AU - Yu, Xiaoqian
AU - Herberg, Artjom
AU - Kuckling, Dirk
ID - 23847
IS - 10
JF - Polymers
SN - 2073-4360
TI - Micellar Organocatalysis Using Smart Polymer Supports: Influence of Thermoresponsive Self-Assembly on Catalytic Activity
VL - 12
ER -
TY - JOUR
AU - Berg, Patrik
AU - Prowald, Carsten Dieter
AU - Kuckling, Dirk
ID - 23856
IS - 2
JF - Gels
SN - 2310-2861
TI - Investigation of Gel Properties of Novel Cryo-Clay-Silica Polymer Networks
VL - 6
ER -
TY - CONF
AB - OpenPGP and S/MIME are two major standards for securing email communication introduced in the early 1990s. Three recent classes of attacks exploit weak cipher modes (EFAIL Malleability Gadgets, or EFAIL-MG), the flexibility of the MIME email structure (EFAIL Direct Exfiltration, or EFAIL-DE), and the Reply action of the email client (REPLY attacks). Although all three break message confidentiality by using standardized email features, only EFAIL-MG has been mitigated in IETF standards with the introduction of AEAD algorithms. So far, no uniform and reliable countermeasures have been adopted by email clients to prevent EFAIL-DE and REPLY attacks. Instead, email clients implement a variety of different ad-hoc countermeasures which are only partially effective, cause interoperability problems, and fragment the secure email ecosystem.We present the first generic countermeasure against both REPLY and EFAIL-DE attacks by checking the decryption context including SMTP headers and MIME structure during decryption. The decryption context is encoded into a string DC and used as Associated Data (AD) in the AEAD encryption. Thus the proposed solution seamlessly extends the EFAIL-MG countermeasures. The decryption context changes whenever an attacker alters the email source code in a critical way, for example, if the attacker changes the MIME structure or adds a new Reply-To header. The proposed solution does not cause any interoperability problems and legacy emails can still be decrypted. We evaluate our approach by implementing the decryption contexts in Thunderbird/Enigmail and by verifying their correct functionality after the email has been transported over all major email providers, including Gmail and iCloud Mail.
AU - Schwenk, Jörg
AU - Brinkmann, Marcus
AU - Poddebniak, Damian
AU - Müller, Jens
AU - Somorovsky, Juraj
AU - Schinzel, Sebastian
ID - 25336
KW - decryption contexts
KW - EFAIL
KW - OpenPGP
KW - S/MIME
KW - AEAD
SN - 9781450370899
T2 - Proceedings of the 2020 ACM SIGSAC Conference on Computer and Communications Security
TI - Mitigation of Attacks on Email End-to-End Encryption
ER -
TY - JOUR
AU - Haddenhorst, Björn
AU - Hüllermeier, Eyke
AU - Kolb, Martin
ID - 25143
JF - International Journal of Approximate Reasoning
SN - 0888-613X
TI - Generalized transitivity: A systematic comparison of concepts with an application to preferences in the Babington Smith model
ER -
TY - GEN
AU - Eberhartinger, Eva
AU - Speitmann, Raffael
AU - Sureth-Sloane, Caren
ID - 24676
SN - 1556-5068
TI - Real Effects of Public Country-by-Country Reporting and the Firm Structure of European Banks
ER -
TY - CHAP
AU - Ulrich, Tanja
ED - Fritzsche, T
ED - Breitenstein, S
ED - Wunderlich, H
ED - Ferchland, L
ED - Krug, R
ID - 33083
T2 - Nur ein Wort? Diagnostik und Therapie von Wortabrufstörungen bei Kindern und Erwachsenen. Spektrum Patholinguistik
TI - Strategieorientierte Therapie mit dem Wortschatzsammler - (nicht nur) für Kinder mit Wortfindungsstörungen
VL - 13
ER -
TY - GEN
AU - Hagengruber, Ruth
ID - 21294
SN - ISSN 1553-9172
T2 - H-France Net
TI - Review Hagengruber Le Ru Émilie Du Châtelet Philosophe
VL - 158
ER -
TY - CHAP
AU - Hagengruber, Ruth
ED - Hagengruber, Ruth Edith
ED - Thorgeirsdottir, Sigridur
ID - 31437
T2 - Methodological Reflections on Women’s Contribution and Influence in the History of Philosophy. Women in the History of Philosophy and Sciences, Vol 3
TI - The Stolen History—Retrieving the History of Women Philosophers and its Methodical Implications
ER -