@article{DoerriesChechkinSchumeretal.2022, author = {Doerries, Timo J. and Chechkin, Aleksei and Schumer, Rina and Metzler, Ralf}, title = {Rate equations, spatial moments, and concentration profiles for mobile-immobile models with power-law and mixed waiting time distributions}, series = {Physical review : E, Statistical, nonlinear and soft matter physics}, volume = {105}, journal = {Physical review : E, Statistical, nonlinear and soft matter physics}, number = {1}, publisher = {The American Institute of Physics}, address = {Woodbury, NY}, issn = {2470-0045}, doi = {10.1103/PhysRevE.105.014105}, pages = {24}, year = {2022}, abstract = {We present a framework for systems in which diffusion-advection transport of a tracer substance in a mobile zone is interrupted by trapping in an immobile zone. Our model unifies different model approaches based on distributed-order diffusion equations, exciton diffusion rate models, and random-walk models for multirate mobile-immobile mass transport. We study various forms for the trapping time dynamics and their effects on the tracer mass in the mobile zone. Moreover, we find the associated breakthrough curves, the tracer density at a fixed point in space as a function of time, and the mobile and immobile concentration profiles and the respective moments of the transport. Specifically, we derive explicit forms for the anomalous transport dynamics and an asymptotic power-law decay of the mobile mass for a Mittag-Leffler trapping time distribution. In our analysis we point out that even for exponential trapping time densities, transient anomalous transport is observed. Our results have direct applications in geophysical contexts, but also in biological, soft matter, and solid state systems.}, language = {en} } @article{HerzogReppertPudelletal.2022, author = {Herzog, Marc and Reppert, Alexander von and Pudell, Jan-Etienne and Henkel, Carsten and Kronseder, Matthias and Back, Christian H. and Maznev, Alexei A. and Bargheer, Matias}, title = {Phonon-dominated energy transport in purely metallic heterostructures}, series = {Advanced functional materials}, volume = {32}, journal = {Advanced functional materials}, number = {41}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-301X}, doi = {10.1002/adfm.202206179}, pages = {8}, year = {2022}, abstract = {Ultrafast X-ray diffraction is used to quantify the transport of energy in laser-excited nanoscale gold-nickel (Au-Ni) bilayers. Electron transport and efficient electron-phonon coupling in Ni convert the laser-deposited energy in the conduction electrons within a few picoseconds into a strong non-equilibrium between hot Ni and cold Au phonons at the bilayer interface. Modeling of the subsequent equilibration dynamics within various two-temperature models confirms that for ultrathin Au films, the thermal transport is dominated by phonons instead of conduction electrons because of the weak electron-phonon coupling in Au.}, language = {en} } @article{WarbyZuZeiskeetal.2022, author = {Warby, Jonathan and Zu, Fengshuo and Zeiske, Stefan and Gutierrez-Partida, Emilio and Frohloff, Lennart and Kahmann, Simon and Frohna, Kyle and Mosconi, Edoardo and Radicchi, Eros and Lang, Felix and Shah, Sahil and Pena-Camargo, Francisco and Hempel, Hannes and Unold, Thomas and Koch, Norbert and Armin, Ardalan and De Angelis, Filippo and Stranks, Samuel D. and Neher, Dieter and Stolterfoht, Martin}, title = {Understanding performance limiting interfacial recombination in pin Perovskite solar cells}, series = {Advanced energy materials}, volume = {12}, journal = {Advanced energy materials}, number = {12}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1614-6832}, doi = {10.1002/aenm.202103567}, pages = {10}, year = {2022}, abstract = {Perovskite semiconductors are an attractive option to overcome the limitations of established silicon based photovoltaic (PV) technologies due to their exceptional opto-electronic properties and their successful integration into multijunction cells. However, the performance of single- and multijunction cells is largely limited by significant nonradiative recombination at the perovskite/organic electron transport layer junctions. In this work, the cause of interfacial recombination at the perovskite/C-60 interface is revealed via a combination of photoluminescence, photoelectron spectroscopy, and first-principle numerical simulations. It is found that the most significant contribution to the total C-60-induced recombination loss occurs within the first monolayer of C-60, rather than in the bulk of C-60 or at the perovskite surface. The experiments show that the C-60 molecules act as deep trap states when in direct contact with the perovskite. It is further demonstrated that by reducing the surface coverage of C-60, the radiative efficiency of the bare perovskite layer can be retained. The findings of this work pave the way toward overcoming one of the most critical remaining performance losses in perovskite solar cells.}, language = {en} } @article{SchwopePiresKurpasetal.2022, author = {Schwope, Axel and Pires, Adriana M. and Kurpas, Jan and Doroshenko, Victor and Suleimanov, Valery F. and Freyberg, Michael and Becker, Werner and Dennerl, Konrad and Haberl, Frank and Lamer, Georg and Maitra, Chandreyee and Potekhin, Alexander Y. and Ramos-Ceja, Miriam E. and Santangelo, Andrea and Traulsen, Iris and Werner, Klaus}, title = {Phase-resolved X-ray spectroscopy of PSR B0656+14 with SRG/eROSITA and XMM-Newton}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {661}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, issn = {0004-6361}, doi = {10.1051/0004-6361/202141105}, pages = {21}, year = {2022}, abstract = {We present a detailed spectroscopic and timing analysis of X-ray observations of the bright pulsar PSR B0656+14. The observations were obtained simultaneously with eROSITA and XMM-Newton during the calibration and performance verification phase of the Spektrum-Roentgen-Gamma mission (SRG). The analysis of the 100 ks deep observation of eROSITA is supported by archival observations of the source, including XMM-Newton, NuSTAR, and NICER. Using XMM-Newton and NICER, we first established an X-ray ephemeris for the time interval 2015 to 2020, which connects all X-ray observations in this period without cycle count alias and phase shifts. The mean eROSITA spectrum clearly reveals an absorption feature originating from the star at 570 eV with a Gaussian sigma of about 70 eV that was tentatively identified in a previous long XMM-Newton observation. A second previously discussed absorption feature occurs at 260-265 eV and is described here as an absorption edge. It could be of atmospheric or of instrumental origin. These absorption features are superposed on various emission components that are phenomenologically described here as the sum of hot (120 eV) and cold (65 eV) blackbody components, both of photospheric origin, and a power law with photon index Gamma = 2 from the magnetosphere. We created energy-dependent light curves and phase-resolved spectra with a high signal-to-noise ratio. The phase-resolved spectroscopy reveals that the Gaussian absorption line at 570 eV is clearly present throughout similar to 60\% of the spin cycle, but it is otherwise undetected. Likewise, its parameters were found to be dependent on phase. The visibility of the line strength coincides in phase with the maximum flux of the hot blackbody. If the line originates from the stellar surface, it nevertheless likely originates from a different location than the hot polar cap. We also present three families of model atmospheres: a magnetized atmosphere, a condensed surface, and a mixed model. They were applied to the mean observed spectrum, whose continuum fit the observed data well. The atmosphere model, however, predicts distances that are too short. For the mixed model, the Gaussian absorption may be interpreted as proton cyclotron absorption in a field as high as 10(14) G, which is significantly higher than the field derived from the moderate observed spin-down.}, language = {en} } @article{YeZhangWarbyetal.2022, author = {Ye, Fangyuan and Zhang, Shuo and Warby, Jonathan and Wu, Jiawei and Gutierrez-Partida, Emilio and Lang, Felix and Shah, Sahil and Saglamkaya, Elifnaz and Sun, Bowen and Zu, Fengshuo and Shoai, Safa and Wang, Haifeng and Stiller, Burkhard and Neher, Dieter and Zhu, Wei-Hong and Stolterfoht, Martin and Wu, Yongzhen}, title = {Overcoming C₆₀-induced interfacial recombination in inverted perovskite solar cells by electron-transporting carborane}, series = {Nature Communications}, volume = {13}, journal = {Nature Communications}, number = {1}, publisher = {Springer Nature}, address = {London}, issn = {2041-1723}, doi = {10.1038/s41467-022-34203-x}, pages = {12}, year = {2022}, abstract = {Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C₆₀ interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C₆₀ interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23\% with a low non-radiative voltage loss of 110 mV, and retain >97\% of the initial efficiency after 400 h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells.}, language = {en} } @article{KupferBauervanRoesteletal.2022, author = {Kupfer, Thomas and Bauer, Evan B. and van Roestel, Jan and Bellm, Eric C. and Bildsten, Lars and Fuller, Jim and Prince, Thomas A. and Heber, Ulrich and Geier, Stephan and Green, Matthew J. and Kulkarni, Shrinivas R. and Bloemen, Steven and Laher, Russ R. and Rusholme, Ben and Schneider, David}, title = {Discovery of a Double-detonation Thermonuclear Supernova Progenitor}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters}, volume = {925}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters}, number = {2}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {2041-8205}, doi = {10.3847/2041-8213/ac48f1}, pages = {10}, year = {2022}, abstract = {We present the discovery of a new double-detonation progenitor system consisting of a hot subdwarf B (sdB) binary with a white dwarf companion with a P (orb) = 76.34179(2) minutes orbital period. Spectroscopic observations are consistent with an sdB star during helium core burning residing on the extreme horizontal branch. Chimera light curves are dominated by ellipsoidal deformation of the sdB star and a weak eclipse of the companion white dwarf. Combining spectroscopic and light curve fits, we find a low-mass sdB star, M (sdB) = 0.383 +/- 0.028 M (circle dot) with a massive white dwarf companion, M (WD) = 0.725 +/- 0.026 M (circle dot). From the eclipses we find a blackbody temperature for the white dwarf of 26,800 K resulting in a cooling age of approximate to 25 Myr whereas our MESA model predicts an sdB age of approximate to 170 Myr. We conclude that the sdB formed first through stable mass transfer followed by a common envelope which led to the formation of the white dwarf companion approximate to 25 Myr ago. Using the MESA stellar evolutionary code we find that the sdB star will start mass transfer in approximate to 6 Myr and in approximate to 60 Myr the white dwarf will reach a total mass of 0.92 M (circle dot) with a thick helium layer of 0.17 M (circle dot). This will lead to a detonation that will likely destroy the white dwarf in a peculiar thermonuclear supernova. PTF1 J2238+7430 is only the second confirmed candidate for a double-detonation thermonuclear supernova. Using both systems we estimate that at least approximate to 1\% of white dwarf thermonuclear supernovae originate from sdB+WD binaries with thick helium layers, consistent with the small number of observed peculiar thermonuclear explosions.}, language = {en} } @article{Nowak2023, author = {Nowak, Anna}, title = {Untersuchung der Qualit{\"a}t von Selbstreflexionstexten zum Physikunterricht}, series = {Studien zum Physik- und Chemielernen}, volume = {371}, journal = {Studien zum Physik- und Chemielernen}, publisher = {Logos}, address = {Berlin}, isbn = {978-3-8325-5739-3}, issn = {1614-8967}, doi = {10.30819/5739}, pages = {419}, year = {2023}, abstract = {Reflexion wird als notwendig f{\"u}r die professionelle Entwicklung von Lehrer:innen und die Verbesserung von Unterricht angesehen, wenngleich aus theoretischer Sicht große Uneinigkeit {\"u}ber den Begriff selbst, den Reflexionsprozess und die damit verbundenen Kompetenzen herrscht. Ziel dieser Arbeit war die Entwicklung, Untersuchung und Weiterentwicklung eines Reflexionsmodells mit einem theoriebasierten, klaren Konzept des Reflexionsprozesses und einem passenden Anspruch an die Reflexionsleistung der Reflektierenden. Grundlage f{\"u}r die empirische Untersuchung waren N = 132 Selbstreflexionstexte von N = 22 Studierenden aus dem Praxissemester Physik. Zur Codierung der Texte wurden vier mittels qualitativer Inhaltsanalyse entwickelte Manuale angewandt. Mit quantitativen Methoden wurden Zusammenh{\"a}nge zwischen strukturellen Elementen, Begr{\"u}ndungen, Inhalten und dem Qualit{\"a}tsmerkmal Reflexionstiefe {\"u}berpr{\"u}ft. Es zeigte sich ein "{\"U}berhang an Negativit{\"a}t": negative Bewertungen, negative Reflexionsausl{\"o}ser und negative Inhalte h{\"a}ngen signifikant positiv mit gr{\"o}ßerer Reflexionstiefe zusammen. Auf Grundlage der empirischen Ergebnisse wurde das Reflexionsmodell mit externaler und internaler Zielorientierung (REIZ) entwickelt. Zudem wurde darauf aufbauend eine Definition f{\"u}r Reflexionstiefe in vier Argumentationsclustern formuliert. F{\"u}r die Lehrkr{\"a}ftebildung wird der in REIZ dargestellte differenzierte Ansatz der Zielorientierung von Reflexion empfohlen.}, language = {de} } @article{ThonigLilliestam2023, author = {Thonig, Richard and Lilliestam, Johan}, title = {Concentrating solar technology policy should encourage high temperatures and modularity to enable spillovers}, series = {AIP conference proceedings}, journal = {AIP conference proceedings}, number = {1}, publisher = {American Institute of Physics}, address = {Melville}, issn = {1551-7616}, doi = {10.1063/5.0149423}, pages = {1 -- 11}, year = {2023}, abstract = {Thermal energy from concentrating solar thermal technologies (CST) may contribute to decarbonizing applications from heating and cooling, desalination, and power generation to commodities such as aluminium, hydrogen, ammonia or sustainable aviation fuels (SAF). So far, successful commercial-scale CST projects are restricted to solar industrial process heat (SIPH) and concentrating solar power (CSP) generation and, at least for the latter, depend on support from public policies that have been stagnating for years. As they are technologically similar, spillovers between SIPH or CSP and other emerging CST could accelerate commercialization across use cases while maximizing the impact of scarce support. Here, we review the technical potential for cross-fertilization between different CST applications and the ability of the current policy regime to enable this potential. Using working temperature as the key variable, we identify different clusters of current and emerging CST technologies. Low-temperature CST (<400℃) applications for heating, cooling and desalination already profit from the significant progress made in line-focussing CSP over the last 15 years. A newly emerging cluster of high temperature CST (>600℃) for solar chemistry and high-grade process heat has significant leverage for spillovers with point-focussing solar tower third-generation CSP currently under development. For these spillovers to happen, however, CSP policy designs would need to prioritize innovation for high working temperature and encourage modular plant design, by adequately remunerating hybridized plants with heat and power in and outputs that include energy sources beyond CST solar fields. This would enable synergies across applications and scales by incentivizing compatibility of modular CST components in multiple sectors and use cases.}, language = {en} } @article{PranavHultzschMusiienkoetal.2023, author = {Pranav, Manasi and Hultzsch, Thomas and Musiienko, Artem and Sun, Bowen and Shukla, Atul and Jaiser, Frank and Shoaee, Safa and Neher, Dieter}, title = {Anticorrelated photoluminescence and free charge generation proves field-assisted exciton dissociation in low-offset PM6:Y5 organic solar cells}, series = {APL materials : high impact open access journal in functional materials science}, volume = {11}, journal = {APL materials : high impact open access journal in functional materials science}, number = {6}, publisher = {AIP Publishing}, address = {Melville}, issn = {2166-532X}, doi = {10.1063/5.0151580}, pages = {8}, year = {2023}, abstract = {Understanding the origin of inefficient photocurrent generation in organic solar cells with low energy offset remains key to realizing high-performance donor-acceptor systems. Here, we probe the origin of field-dependent free-charge generation and photoluminescence in wnon-fullereneacceptor (NFA)-based organic solar cells using the polymer PM6 and the NFA Y5-a non-halogenated sibling to Y6, with a smaller energetic offset to PM6. By performing time-delayed collection field (TDCF) measurements on a variety of samples with different electron transport layers and active layer thickness, we show that the fill factor and photocurrent are limited by field-dependent free charge generation in the bulk of the blend. We also introduce a new method of TDCF called m-TDCF to prove the absence of artifacts from non-geminate recombination of photogenerated and dark charge carriers near the electrodes. We then correlate free charge generation with steady-state photoluminescence intensity and find perfect anticorrelation between these two properties. Through this, we conclude that photocurrent generation in this low-offset system is entirely controlled by the field-dependent dissociation of local excitons into charge-transfer states. (c) 2023 Author(s).}, language = {en} } @article{HovhannisyanNematiHenkeletal.2023, author = {Hovhannisyan, Karen V. and Nemati, Somayyeh and Henkel, Carsten and Anders, Janet}, title = {Long-time equilibration can determine transient thermality}, series = {PRX Quantum}, volume = {4}, journal = {PRX Quantum}, number = {3}, publisher = {American Physical Society}, address = {College Park}, issn = {2691-3399}, doi = {10.1103/PRXQuantum.4.030321}, pages = {23}, year = {2023}, abstract = {When two initially thermal many-body systems start to interact strongly, their transient states quickly become non-Gibbsian, even if the systems eventually equilibrate. To see beyond this apparent lack of structure during the transient regime, we use a refined notion of thermality, which we call g-local. A system is g-locally thermal if the states of all its small subsystems are marginals of global thermal states. We numerically demonstrate for two harmonic lattices that whenever the total system equilibrates in the long run, each lattice remains g-locally thermal at all times, including the transient regime. This is true even when the lattices have long-range interactions within them. In all cases, we find that the equilibrium is described by the generalized Gibbs ensemble, with three-dimensional lattices requiring special treatment due to their extended set of conserved charges. We compare our findings with the well-known two-temperature model. While its standard form is not valid beyond weak coupling, we show that at strong coupling it can be partially salvaged by adopting the concept of a g-local temperature.}, language = {en} }