@article{22053, author = {{Spychala, K. J. and Mackwitz, P. and Widhalm, A. and Berth, G. and Zrenner, A.}}, issn = {{0021-8979}}, journal = {{Journal of Applied Physics}}, title = {{{Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime}}}, doi = {{10.1063/1.5133476}}, year = {{2020}}, } @article{22054, author = {{Spychala, K. J. and Mackwitz, P. and Widhalm, A. and Berth, Gerhard and Zrenner, Artur}}, issn = {{0021-8979}}, journal = {{Journal of Applied Physics}}, title = {{{Spatially resolved light field analysis of the second-harmonic signal of χ(2)-materials in the tight focusing regime}}}, doi = {{10.1063/1.5133476}}, year = {{2020}}, } @article{16457, author = {{Lehmann, T and Büchel, D and Cockcroft, J and Louw, Q and Baumeister, Jochen}}, issn = {{0306-4522}}, journal = {{Neuroscience}}, pages = {{63--72}}, title = {{{Modulations of Inter-Hemispherical Phase Coupling in Human Single Leg Stance.}}}, doi = {{10.1016/j.neuroscience.2020.01.029}}, volume = {{430}}, year = {{2020}}, } @article{16458, author = {{Bonnette, S and Diekfuss, JA and Grooms, DR and Kiefer, AW and Riley, MA and Riehm, C and Moore, C and Barber Foss, KD and DiCesare, CA and Baumeister, Jochen and Myer, GD}}, issn = {{0048-5772}}, journal = {{Psychophysiology}}, number = {{4}}, pages = {{e13530}}, title = {{{Electrocortical dynamics differentiate athletes exhibiting low- and high- ACL injury risk biomechanics.}}}, doi = {{10.1111/psyp.13530}}, volume = {{57}}, year = {{2020}}, } @article{16839, author = {{Sain, Basudeb and Zentgraf, Thomas}}, issn = {{2047-7538}}, journal = {{Light: Science & Applications}}, pages = {{67}}, title = {{{Metasurfaces help lasers to mode-lock}}}, doi = {{10.1038/s41377-020-0312-1}}, volume = {{9}}, year = {{2020}}, } @article{16931, author = {{Zhou, Hongqiang and Sain, Basudeb and Wang, Yongtian and Schlickriede, Christian and Zhao, Ruizhe and Zhang, Xue and Wei, Qunshuo and Li, Xiaowei and Huang, Lingling and Zentgraf, Thomas}}, issn = {{1936-0851}}, journal = {{ACS Nano}}, number = {{5}}, pages = {{5553–5559}}, title = {{{Polarization-Encrypted Orbital Angular Momentum Multiplexed Metasurface Holography}}}, doi = {{10.1021/acsnano.9b09814}}, volume = {{14}}, year = {{2020}}, } @article{16944, author = {{Schlickriede, Christian and Kruk, Sergey S. and Wang, Lei and Sain, Basudeb and Kivshar, Yuri and Zentgraf, Thomas}}, issn = {{1530-6984}}, journal = {{Nano Letters}}, number = {{6}}, pages = {{4370–4376}}, title = {{{Nonlinear imaging with all-dielectric metasurfaces}}}, doi = {{10.1021/acs.nanolett.0c01105}}, volume = {{20}}, year = {{2020}}, } @article{15480, abstract = {{The nonlinear processes of frequency conversion such as second harmonic generation (SHG) usually obey certain selection rules, resulting from the preservation of different kinds of physical quantities, e.g. the angular momentum. For the SHG created by a monolayer of transition-metal dichalcogenides (TMDCs) such as WS2, the valley-exciton locked selection rule predicts an SHG signal in the cross-polarization state. By combining plasmonic nanostructures with a monolayer of TMDC, a hybrid metasurface is realized, which affects this nonlinear process because of an additional polarization conversion process. Here, we observe that the plasmonic metasurface modifies the light-matter interaction with the TMDC, resulting in an SHG signal that is co-polarized with respect to the incident field, which is usually forbidden for the monolayers of TMDC. We fabricate such hybrid metasurfaces by placing plasmonic nanorods on top of a monolayer WS2 and study the valley-exciton locked SHG emission from such system for different parameters, such as wavelength and polarization. Furthermore, we show the potential of the hybrid metasurface for tailoring nonlinear processes by adding additional phase information to the SHG signal using the Pancharatnam-Berry phase effect. This allows direct tailoring of the SHG emission to the far-field.}}, author = {{Spreyer, Florian and Zhao, Ruizhe and Huang, Lingling and Zentgraf, Thomas}}, issn = {{2192-8614}}, journal = {{Nanophotonics}}, number = {{2}}, pages = {{351–360}}, title = {{{Second harmonic imaging of plasmonic Pancharatnam-Berry phase metasurfaces coupled to monolayers of WS2}}}, doi = {{10.1515/nanoph-2019-0378}}, volume = {{9}}, year = {{2020}}, } @article{15714, author = {{Riedl, T. and Kunnathully, V. S. and Trapp, A. and Langer, T. and Reuter, D. and Lindner, J. K. N.}}, issn = {{2475-9953}}, journal = {{Physical Review Materials}}, title = {{{Strain-driven InAs island growth on top of GaAs(111) nanopillars}}}, doi = {{10.1103/physrevmaterials.4.014602}}, year = {{2020}}, } @article{16197, abstract = {{Nonlinear Pancharatnam–Berry phase metasurfaces facilitate the nontrivial phase modulation for frequency conversion processes by leveraging photon‐spin dependent nonlinear geometric‐phases. However, plasmonic metasurfaces show some severe limitation for nonlinear frequency conversion due to the intrinsic high ohmic loss and low damage threshold of plasmonic nanostructures. Here, the nonlinear geometric‐phases associated with the third‐harmonic generation process occurring in all‐dielectric metasurfaces is studied systematically, which are composed of silicon nanofins with different in‐plane rotational symmetries. It is found that the wave coupling among different field components of the resonant fundamental field gives rise to the appearance of different nonlinear geometric‐phases of the generated third‐harmonic signals. The experimental observations of the nonlinear beam steering and nonlinear holography realized in this work by all‐dielectric geometric‐phase metasurfaces are well explained with the developed theory. This work offers a new physical picture to understand the nonlinear optical process occurring at nanoscale dielectric resonators and will help in the design of nonlinear metasurfaces with tailored phase properties.}}, author = {{Liu, Bingyi and Sain, Basudeb and Reineke, Bernhard and Zhao, Ruizhe and Meier, Cedrik and Huang, Lingling and Jiang, Yongyuan and Zentgraf, Thomas}}, issn = {{2195-1071}}, journal = {{Advanced Optical Materials}}, number = {{9}}, publisher = {{Wiley}}, title = {{{Nonlinear Wavefront Control by Geometric-Phase Dielectric Metasurfaces: Influence of Mode Field and Rotational Symmetry}}}, doi = {{10.1002/adom.201902050}}, volume = {{8}}, year = {{2020}}, } @article{19844, abstract = {{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.}}, author = {{Elizabeth, Amala and Sahoo, Sudhir K. and Lockhorn, David and Timmer, Alexander and Aghdassi, Nabi and Zacharias, Helmut and Kühne, Thomas and Siebentritt, Susanne and Mirhosseini, Hossein and Mönig, Harry}}, journal = {{Phys. Rev. Materials}}, pages = {{063401}}, publisher = {{American Physical Society}}, title = {{{ Oxidation/reduction cycles and their reversible effect on the dipole formation at CuInSe2 surfaces}}}, doi = {{10.1103/PhysRevMaterials.4.063401}}, volume = {{4}}, year = {{2020}}, } @article{21112, abstract = {{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.}}, author = {{Mirhosseini, S. Hossein and Kormath Madam Raghupathy, Ramya and Sahoo, Sudhir K. and Wiebeler, Hendrik and Chugh, Manjusha and Kühne, Thomas}}, journal = {{Phys. Chem. Chem. Phys.}}, pages = {{26682--26701}}, publisher = {{The Royal Society of Chemistry}}, title = {{{In silico investigation of Cu(In,Ga)Se2-based solar cells}}}, doi = {{10.1039/D0CP04712K}}, volume = {{22}}, year = {{2020}}, } @article{21240, abstract = {{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.}}, author = {{Yu, Minghao and Chandrasekhar, Naisa and Kormath Madam Raghupathy, Ramya and Ly, Khoa Hoang and Zhang, Haozhe and Dmitrieva, Evgenia and Liang, Chaolun and Lu, Xihong and Kühne, Thomas and Mirhosseini, S. Hossein and Weidinger, Inez M. and Feng, Xinliang}}, issn = {{0002-7863}}, journal = {{Journal of the American Chemical Society}}, number = {{46}}, pages = {{19570--19578}}, publisher = {{American Chemical Society}}, title = {{{A High-Rate Two-Dimensional Polyarylimide Covalent Organic Framework Anode for Aqueous Zn-Ion Energy Storage Devices}}}, doi = {{10.1021/jacs.0c07992}}, volume = {{142}}, year = {{2020}}, } @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}}, }