@article{17374, abstract = {{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support our results with the study of FAPbBr3 which expands the identification of vibrational modes to the previously unpublished low frequency region (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).}}, author = {{Ibaceta-Jaña, Josefa and Muydinov, Ruslan and Rosado, Pamela and Mirhosseini, Hossein and Chugh, Manjusha and Nazarenko, Olga and Dirin, Dmitry N. and Heinrich, Dirk and Wagner, Markus R. and Kühne, Thomas and Szyszka, Bernd and Kovalenko, Maksym V. and Hoffmann, Axel}}, journal = {{Phys. Chem. Chem. Phys.}}, pages = {{5604--5614}}, publisher = {{The Royal Society of Chemistry}}, title = {{{Vibrational dynamics in lead halide hybrid perovskites investigated by Raman spectroscopy}}}, doi = {{10.1039/C9CP06568G}}, volume = {{22}}, year = {{2020}}, } @article{17376, abstract = {{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.}}, author = {{Schöppe, Philipp and Schönherr, Sven and Chugh, Manjusha and Mirhosseini, Hossein and Jackson, Philip and Wuerz, Roland and Ritzer, Maurizio and Johannes, Andreas and Martínez-Criado, Gema and Wisniewski, Wolfgang and Schwarz, Torsten and T. Plass, Christian and Hafermann, Martin and Kühne, Thomas and S. Schnohr, Claudia and Ronning, Carsten}}, issn = {{2211-2855}}, journal = {{Nano Energy}}, pages = {{104622}}, title = {{{Revealing the origin of the beneficial effect of cesium in highly efficient Cu(In,Ga)Se2 solar cells}}}, doi = {{https://doi.org/10.1016/j.nanoen.2020.104622}}, volume = {{71}}, year = {{2020}}, } @article{23855, author = {{Aly, Kamal I. and Sun, Jingjiang and Kuckling, Dirk and Younis, Osama}}, issn = {{1022-9760}}, journal = {{Journal of Polymer Research}}, publisher = {{Springer}}, title = {{{Polyester resins based on soybean oil: synthesis and characterization}}}, doi = {{10.1007/s10965-020-02244-9}}, volume = {{27}}, year = {{2020}}, } @article{23852, author = {{Li, Jie and Ji, Chendong and Lü, Baozhong and Rodin, Maksim and Paradies, Jan and Yin, Meizhen and Kuckling, Dirk}}, issn = {{1944-8244}}, journal = {{ACS Applied Materials & Interfaces}}, number = {{33}}, pages = {{36873--36881}}, title = {{{Dually Crosslinked Supramolecular Hydrogel for Cancer Biomarker Sensing}}}, doi = {{10.1021/acsami.0c08722}}, volume = {{12}}, year = {{2020}}, } @article{23849, author = {{Berg, Patrik and Obst, Franziska and Simon, David and Richter, Andreas and Appelhans, Dietmar and Kuckling, Dirk}}, issn = {{1434-193X}}, journal = {{European Journal of Organic Chemistry}}, pages = {{5765--5774}}, publisher = {{Wiley-VCH}}, title = {{{Novel Application of Polymer Networks Carrying Tertiary Amines as a Catalyst Inside Microflow Reactors Used for Knoevenagel Reactions}}}, doi = {{10.1002/ejoc.202000978}}, year = {{2020}}, } @article{23848, author = {{Berg, Marie-Theres and Mertens, Chiel and Du Prez, Filip and Kühne, Thomas D. and Herberg, Artjom and Kuckling, Dirk}}, issn = {{2046-2069}}, journal = {{RSC Advances}}, pages = {{35245--35252}}, publisher = {{RSC}}, title = {{{Analysis of sequence-defined oligomers through Advanced Polymer Chromatography™ – mass spectrometry hyphenation}}}, doi = {{10.1039/d0ra06419j}}, volume = {{10}}, year = {{2020}}, } @article{23847, author = {{Yu, Xiaoqian and Herberg, Artjom and Kuckling, Dirk}}, issn = {{2073-4360}}, journal = {{Polymers}}, number = {{10}}, publisher = {{MDPI}}, title = {{{Micellar Organocatalysis Using Smart Polymer Supports: Influence of Thermoresponsive Self-Assembly on Catalytic Activity}}}, doi = {{10.3390/polym12102265}}, volume = {{12}}, year = {{2020}}, } @article{23856, author = {{Berg, Patrik and Prowald, Carsten Dieter and Kuckling, Dirk}}, issn = {{2310-2861}}, journal = {{Gels}}, number = {{2}}, publisher = {{MDPI}}, title = {{{Investigation of Gel Properties of Novel Cryo-Clay-Silica Polymer Networks}}}, doi = {{10.3390/gels6020011}}, volume = {{6}}, year = {{2020}}, } @article{32456, author = {{Letafatkar, Amir and Rabiei, Pouya and Ghanati, Hadi Abbaszadeh and Khosrokiani, Zohre and Ghahremani, Naji and Gokeler, Alli}}, issn = {{1824-7490}}, journal = {{Sport Sciences for Health}}, keywords = {{Orthopedics and Sports Medicine}}, number = {{4}}, pages = {{737--745}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Training athletes with an external attentional focus enhances athletic performance during countermovement jump}}}, doi = {{10.1007/s11332-020-00652-4}}, volume = {{16}}, year = {{2020}}, } @article{32455, author = {{Haines, Mackenzie and Murray, Amanda M. and Glaviano, Neal R. and Gokeler, Alli and Norte, Grant E.}}, issn = {{0167-9457}}, journal = {{Human Movement Science}}, keywords = {{Experimental and Cognitive Psychology, Orthopedics and Sports Medicine, General Medicine, Biophysics}}, publisher = {{Elsevier BV}}, title = {{{Restricting ankle dorsiflexion does not mitigate the benefits of external focus of attention on landing biomechanics in healthy females}}}, doi = {{10.1016/j.humov.2020.102719}}, volume = {{74}}, year = {{2020}}, } @article{34643, author = {{Liphardt, L. and Suematsu, K. and Grundmeier, Guido}}, issn = {{0360-3199}}, journal = {{International Journal of Hydrogen Energy}}, keywords = {{Energy Engineering and Power Technology, Condensed Matter Physics, Fuel Technology, Renewable Energy, Sustainability and the Environment}}, number = {{5}}, pages = {{4399--4406}}, publisher = {{Elsevier BV}}, title = {{{Kinetic studies of cathode degradation on PEM fuel cell short stack level undergoing freeze startups with different states of residual water and current draws}}}, doi = {{10.1016/j.ijhydene.2020.10.273}}, volume = {{46}}, year = {{2020}}, } @article{29526, author = {{van der Meer, R. and Renema, J. J. and Brecht, Benjamin and Silberhorn, Christine and Pinkse, P. W. H.}}, issn = {{2469-9926}}, journal = {{Physical Review A}}, number = {{6}}, publisher = {{American Physical Society (APS)}}, title = {{{Optimizing spontaneous parametric down-conversion sources for boson sampling}}}, doi = {{10.1103/physreva.101.063821}}, volume = {{101}}, year = {{2020}}, } @article{27022, abstract = {{Abstract Purpose While observational studies revealed inverse associations between serum vitamin D levels [25(OH)D] and depression, randomized controlled trials (RCT) in children and adolescents are lacking. This RCT examined the effect of an untreated vitamin D deficiency compared to an immediate vitamin D3 supplementation on depression scores in children and adolescents during standard day and in-patient psychiatric treatment. Methods Patients with vitamin D deficiency [25(OH)D ≤ 30 nmol/l] and at least mild depression [Beck Depression Inventory II (BDI-II) > 13] (n = 113) were 1:1 randomized into verum (VG; 2640 IU vitamin D3/d) or placebo group (PG) in a double-blind manner. During the intervention period of 28 days, both groups additionally received treatment as usual. BDI-II scores were assessed as primary outcome, DISYPS-II (Diagnostic System for Mental Disorders in Childhood and Adolescence, Self- and Parent Rating) and serum total 25(OH)D were secondary outcomes. Results At admission, 49.3% of the screened patients (n = 280) had vitamin D deficiency. Although the intervention led to a higher increase of 25(OH)D levels in the VG than in the PG (treatment difference: + 14 ng/ml; 95% CI 4.86–23.77; p = 0.003), the change in BDI-II scores did not differ (+ 1.3; 95% CI − 2.22 to 4.81; p = 0.466). In contrast, DISYPS parental ratings revealed pronounced improvements of depressive symptoms in the VG (− 0.68; 95% CI − 1.23 to − 0.13; p = 0.016). Conclusion Whereas this study failed to show a vitamin D supplementation effect on self-rated depression in adolescent in- or daycare patients, parents reported less depressive symptoms in VG at the end of our study. Future trials should consider clinician-rated depressive symptoms as primary outcome. Trial registration “German Clinical Trials Register” (https://www.drks.de), registration number: DRKS00009758 }}, author = {{Libuda, Lars and Timmesfeld, Nina and Antel, Jochen and Hirtz, Raphael and Bauer, Jens and Führer, Dagmar and Zwanziger, Denise and Öztürk, Dana and Langenbach, Gina and Hahn, Denise and Ring, Stefanie and Peters, Triinu and Hinney, Anke and Bühlmeier, Judith and Hebebrand, Johannes and Grasemann, Corinna and Föcker, Manuel}}, issn = {{1436-6207}}, journal = {{European Journal of Nutrition}}, pages = {{3415--3424}}, title = {{{Effect of vitamin D deficiency on depressive symptoms in child and adolescent psychiatric patients: results of a randomized controlled trial}}}, doi = {{10.1007/s00394-020-02176-6}}, year = {{2020}}, } @article{27018, abstract = {{Acute anorexia nervosa (AN) constitutes an extreme physiological state. We aimed to detect state related metabolic alterations during inpatient admission and upon short- and long-term weight regain. In addition, we tested the hypothesis that metabolite concentrations adapt to those of healthy controls (HC) after long-term weight regain. Thirty-five female adolescents with AN and 25 female HC were recruited. Based on a targeted approach 187 metabolite concentrations were detected at inpatient admission (T0), after short-term weight recovery (T1; half of target-weight) and close to target weight (T2). Pattern hunter and time course analysis were performed. The highest number of significant differences in metabolite concentrations (N = 32) were observed between HC and T1. According to the detected main pattern, metabolite concentrations at T2 became more similar to those of HC. The course of single metabolite concentrations (e.g., glutamic acid) revealed different metabolic subtypes within the study sample. Patients with AN after short-term weight regain are in a greater “metabolic imbalance” than at starvation. After long-term weight regain, patients reach a metabolite profile similar to HC. Our results might be confounded by different metabolic subtypes of patients with AN.}}, author = {{Föcker, Manuel and Cecil, Alexander and Prehn, Cornelia and Adamski, Jerzy and Albrecht, Muriel and Adams, Frederike and Hinney, Anke and Libuda, Lars and Bühlmeier, Judith and Hebebrand, Johannes and Peters, Triinu and Antel, Jochen}}, issn = {{2218-1989}}, journal = {{Metabolites}}, title = {{{Evaluation of Metabolic Profiles of Patients with Anorexia Nervosa at Inpatient Admission, Short- and Long-Term Weight Regain—Descriptive and Pattern Analysis}}}, doi = {{10.3390/metabo11010007}}, year = {{2020}}, } @article{33646, author = {{Majumdar, I. and Sahoo, S.K. and Parvan, V. and Mirhosseini, Hossein and Chacko, B. and Wang, Y. and Greiner, D. and Kühne, Thomas and Schlatmann, R. and Lauermann, I.}}, issn = {{0169-4332}}, journal = {{Applied Surface Science}}, keywords = {{Surfaces, Coatings and Films, Condensed Matter Physics, Surfaces and Interfaces, General Physics and Astronomy, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Effects of KF and RbF treatments on Cu(In,Ga)Se2-based solar cells: A combined photoelectron spectroscopy and DFT study}}}, doi = {{10.1016/j.apsusc.2020.148085}}, volume = {{538}}, year = {{2020}}, } @article{33647, author = {{Kossmann, Janina and Piankova, Diana and Tarakina, Nadezda V. and Heske, Julian Joachim and Kühne, Thomas and Schmidt, Johannes and Antonietti, Markus and López-Salas, Nieves}}, issn = {{0008-6223}}, journal = {{Carbon}}, keywords = {{General Chemistry, General Materials Science}}, pages = {{497--505}}, publisher = {{Elsevier BV}}, title = {{{Guanine condensates as covalent materials and the concept of cryptopores}}}, doi = {{10.1016/j.carbon.2020.10.047}}, volume = {{172}}, year = {{2020}}, } @article{20157, author = {{Thiele, Frederik and vom Bruch, Felix and Quiring, Victor and Ricken, Raimund and Herrmann, Harald and Eigner, Christof and Silberhorn, Christine and Bartley, Tim}}, issn = {{1094-4087}}, journal = {{Optics Express}}, title = {{{Cryogenic electro-optic polarisation conversion in titanium in-diffused lithium niobate waveguides}}}, doi = {{10.1364/oe.399818}}, year = {{2020}}, } @inproceedings{21719, abstract = {{We fabricate silicon tapers to increase the mode overlap of superconducting detectors on Ti:LiNbO3 waveguides. Mode images show a reduction in mode size from 6 µm to 2 µm FWHM, agreeing with beam propagation simulations.}}, author = {{Protte, Maximilian and Ebers, Lena and Hammer, Manfred and Höpker, Jan Philipp and Albert, Maximilian and Quiring, Viktor and Meier, Cedrik and Förstner, Jens and Silberhorn, Christine and Bartley, Tim}}, booktitle = {{OSA Quantum 2.0 Conference}}, isbn = {{9781943580811}}, keywords = {{tet_topic_waveguide}}, title = {{{Towards Semiconductor-Superconductor-Crystal Hybrid Integration for Quantum Photonics}}}, doi = {{10.1364/quantum.2020.qth7a.8}}, year = {{2020}}, } @article{27021, author = {{Jansen, Kathrin and Tempes, Jana and Drozdowska, Alina and Gutmann, Maike and Falkenstein, Michael and Buyken, Anette and Libuda, Lars and Rudolf, Henrik and Lücke, Thomas and Kersting, Mathilde}}, issn = {{0954-3007}}, journal = {{European Journal of Clinical Nutrition}}, pages = {{757--764}}, title = {{{Short-term effects of carbohydrates differing in glycemic index (GI) consumed at lunch on children’s cognitive function in a randomized crossover study}}}, doi = {{10.1038/s41430-020-0600-0}}, year = {{2020}}, } @article{35328, author = {{Wortmann, Martin and Frese, Natalie and Keil, Waldemar and Brikmann, Johannes and Biedinger, Jan and Brockhagen, Bennet and Reiss, Günter and Schmidt, Claudia and Gölzhäuser, Armin and Moritzer, Elmar and Hüsgen, Bruno}}, issn = {{2637-6105}}, journal = {{ACS Applied Polymer Materials}}, keywords = {{Organic Chemistry, Polymers and Plastics, Process Chemistry and Technology}}, number = {{11}}, pages = {{4719--4732}}, publisher = {{American Chemical Society (ACS)}}, title = {{{The Deterioration Mechanism of Silicone Molds in Polyurethane Vacuum Casting}}}, doi = {{10.1021/acsapm.0c00744}}, volume = {{2}}, year = {{2020}}, }