cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Influence of Compound Target Preparation, Sputtering Power and Substrate Temperature on the Achievement of Cu(In,Ga)Se2 Precursors Suitable to Get High Efficiency Solar Cells
Creators: name: Bosio, A.
name: Rosa, G.
name: Mazzamuto, S.
name: Romeo, A.
name: Piccinelli, F.
name: Romeo, N.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1233-1236
description: In the past, we reported Cu(In,Ga)Se2 solar cells exhibiting an efficiency of about 16% obtained by
sputtering and selenization, starting from targets of InSe, GaSe and Cu.
Here, we report on the requirements, which have to be respected in order to get good precursors suitable to give high
efficiency by simple selenization in a Se-vapour. First of all, the targets of InSe and GaSe should exhibit a density
higher than 97% to avoid their damage during the sputtering deposition. Secondly, especially for InSe, the sputtering
power has to be regulated. If it is too low then films with excess of Se are obtained and this can cause the peeling of
the film during selenization. If the sputtering power is too high, segregation of In on the surface of the target is
observed. We found out that the right sputtering power is about 3.8 W/cm2 corresponding to a deposition rate of ~ 20
Å/sec. Another important parameter is the substrate temperature. During the InSe deposition, if the temperature
substrate is higher than 670 K then the film will contain In-excess. If the temperature is lower than 470 K the film can
contain Se-excess. The substrate temperature is less critical when GaSe or Cu are deposited. In this case a higher
substrate temperature, in the range 670 ÷ 720 K, is used in order to get a good mixing of InSe, GaSe and Cu.
During the selenization, an important parameter to be considered is the deposition rate of Se. It has been found out
that the grain size of the finished Cu(In,Ga)Se2 film is larger when the evaporation rate of Se is not too high and it is
around 1 μm/sec.
By controlling the above parameters, high quality Cu(In,Ga)Se2 films with a grain size larger than 1 μm are
reproducibly obtained. These films, used to prepare solar cells, gave us the possibility to obtain an efficiency larger
than 16%.
Extreme Vortex States and the Growth of Enstrophy in 3D Incompressible Flows
Creators: name: Ayala, Diego
name: Protas, Bartosz
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In this investigation we study extreme vortex states defined as incompressible velocity fields with prescribed enstrophy $\mathcal{E}_0$ which maximize the instantaneous rate of growth of enstrophy $d\mathcal{E}/dt$. We provide {an analytic} characterization of these extreme vortex states in the limit of vanishing enstrophy $\mathcal{E}_0$ and, in particular, show that the Taylor-Green vortex is in fact a local maximizer of $d\mathcal{E} / dt$ {in this limit}. For finite values of enstrophy, the extreme vortex states are computed numerically by solving a constrained variational optimization problem using a suitable gradient method. In combination with a continuation approach, this allows us to construct an entire family of maximizing vortex states parameterized by their enstrophy. We also confirm the findings of the seminal study by Lu & Doering (2008) that these extreme vortex states saturate (up to a numerical prefactor) the fundamental bound $d\mathcal{E} / dt < C \, \mathcal{E}^3$, for some constant $C > 0$. The time evolution corresponding to these extreme vortex states leads to a larger growth of enstrophy than the growth achieved by any of the commonly used initial conditions with the same enstrophy $\mathcal{E}_0$. However, based on several different diagnostics, there is no evidence of any tendency towards singularity formation in finite time. Finally, we discuss possible physical reasons why the initially large growth of enstrophy is not sustained for longer times.
description: 43 pages, 11 figures; accepted for publication in "Journal of Fluid Mechanics"
Strong coupling between excitons and quasi-Bound states in the continuum in the bulk transition metal dichalcogenides
Creators: name: Qin, Meibao
name: Duan, Junyi
name: Xiao, Shuyuan
name: Liu, Wenxing
name: Yu, Tianbao
name: Wang, Tongbiao
name: Liao, Qinghua
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We investigate the strong coupling between the excitons and quasi-bound states in the continuum (BIC) resonance in a bulk WS$_2$ metasurface. Here we employ the bulk WS$_2$ to construct an ultrathin nanodisk metasurface, supporting the symmetry-protected magnetic dipole (MD) quasi-BIC resonance, which can self-hybridize with the excitons and lead to a strong light-matter interaction enhancement within the structure without the necessity for an external cavity. This strong coupling can be charactered by the considerable Rabi splitting of 159 meV and the clearly anti-crossing behavior appeared in the absorption spectrum. Furthermore, we analyze such light-matter coupling by constructing a Hamiltonian model including the surplus excitons, and tune the interaction from weak coupling to strong coupling regimes via the tunability radiation loss of the quasi-BIC resonance. Our results have great potential for manipulating the exciton-polaritons at room temperature, and provide a promising prospect for photonic devices that exploit strong coupling in applications.
On regularity lemmas and their algorithmic applications
Creators: name: Fox, Jacob
name: Lovász, László Miklós
name: Zhao, Yufei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Szemerédi's regularity lemma and its variants are some of the most powerful tools in combinatorics. In this paper, we establish several results around the regularity lemma. First, we prove that whether or not we include the condition that the desired vertex partition in the regularity lemma is equitable has a minimal effect on the number of parts of the partition. Second, we use an algorithmic version of the (weak) Frieze--Kannan regularity lemma to give a substantially faster deterministic approximation algorithm for counting subgraphs in a graph. Previously, only an exponential dependence for the running time on the error parameter was known, and we improve it to a polynomial dependence. Third, we revisit the problem of finding an algorithmic regularity lemma, giving approximation algorithms for several co-NP-complete problems. We show how to use the weak Frieze--Kannan regularity lemma to approximate the regularity of a pair of vertex subsets. We also show how to quickly find, for each $ε'>ε$, an $ε'$-regular partition with $k$ parts if there exists an $ε$-regular partition with $k$ parts. Finally, we give a simple proof of the permutation regularity lemma which improves the tower-type bound on the number of parts in the previous proofs to a single exponential bound.
description: Erratum added at the end. See also arXiv:1801.05037
Changes in Temperature-Coefficient of the Diode Model Caused by Light-Induced Degradation of a-Si/µc-Si Solar Cells
Creators: name: Weicht, J.A.
name: Hamelmann, F.U.
name: Behrens, G.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
Silicon-based Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1253-1255
description: In our work we observe the temperature coefficients before and after light-induced degradation of
amorphous/micro-crystalline (a-Si/μc-Si) tandem silicon-based solar cells. We show that during light-induced
degradation the temperature parameters of the serial and parallel resistance, photo current and the saturation current in
the diode model change: the temperature has a stronger effect after the light-induced degradation, the temperaturecoefficient
of silicon-based thin film solar cells varies during the light-induced degradation.
Solution of the BEC to BCS Quench in One Dimension
Creators: name: Rylands, Colin
name: Calabrese, Pasquale
name: Bertini, Bruno
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: A gas of interacting fermions confined in a quasi one-dimensional geometry shows a BEC to BCS crossover upon slowly driving its coupling constant through a confinement-induced resonance. On one side of the crossover the fermions form tightly-bound bosonic molecules behaving as a repulsive Bose gas, while on the other they form Cooper pairs, whose size is much larger than the average inter-particle distance. Here we consider the situation arising when the coupling constant is varied suddenly from the BEC to the BCS value. Namely, we study a BEC-to-BCS quench. By exploiting a suitable continuum limit of recently discovered solvable quenches in the Hubbard model, we show that the local stationary state reached at large times after the quench can be determined exactly by means of the Quench Action approach. We provide an experimentally-accessible characterisation of the stationary state by computing local pair correlation function as well as the quasi-particle distribution functions. We find that the steady state is increasingly dominated by two particle spin singlet bound states for stronger interaction strength but that bound state formation is inhibited at larger BEC density. The bound state rapidity distribution displays quartic power law decay suggesting a violation of Tan's contact relations.
description: 5 pages, 2 figures
Concatenation theorems for anti-Gowers-uniform functions and Host-Kra characteristic factors
Creators: name: Tao, Terence
name: Ziegler, Tamar
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 11B30, 37A15

description: We establish a number of "concatenation theorems" that assert, roughly speaking, that if a function exhibits "polynomial" (or "Gowers anti-uniform", "uniformly almost periodic", or "nilsequence") behaviour in two different directions separately, then it also exhibits the same behavior (but at higher degree) in both directions jointly. Among other things, this allows one to control averaged local Gowers uniformity norms by global Gowers uniformity norms. In a sequel to this paper, we will apply such control to obtain asymptotics for "polynomial progressions" $n+P_1(r),\dots,n+P_k(r)$ in various sets of integers, such as the prime numbers.
description: 60 pages, no figures. Formatted using the Discrete Analysis style file (now with corrected title)
Evolutionary Optimization of TCO/Mesh Electrical Contacts in CIGS Solar Cells
Creators: name: Losio, P.A.
name: Feurer, T.
name: Buecheler, S.
name: Ruhstaller, B.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1237-1240
description: State of the art solar cells often require a combination of TCO and metallic grid to efficiently transport the generated
current to an external circuit. Optimization of these complex contacts based on several materials with different conductivities
and geometries is often still based on a traditional approach consisting of simple analytical formulas and
empirical knowledge in spite of the complexity. An evolutionary algorithm combined with an electrical 2D+1D FEM
model is used to optimize the shape of the metallic contact considering the material conductivities, the geometry and
shadowing.
The performance of two automatically designed contacts is compared with experimental results of CIGS solar cells
prepared with two different TCO thicknesses
Quantum interference in gravitational particle production
Creators: name: Basso, Edward
name: Chung, Daniel J. H.
name: Kolb, Edward W.
name: Long, Andrew J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Previous numerical investigations of gravitational particle production during the coherent oscillation period of inflation displayed unexplained fluctuations in the spectral density of the produced particles. We argue that these features are due to the quantum interference of the coherent scattering reactions that produce the particles. We provide accurate analytic formulae to compute the particle production amplitude for a conformally-coupled scalar field, including the interference effect in the kinematic region where the production can be interpreted as inflaton scattering into scalar final states via graviton exchange.
description: 19 pages + appendices and references, 3 figures, v2 - references added, matches JHEP
The Negative Influences of Excessive Oxygen Gas on the Electrical Properties of ITO Films Deposited by Magnetron Sputtering
Creators: name: Tan, X.
name: Peng, S.
name: Cao, X.
name: Pan, J.
name: Wang, X.
name: Delahoy, A.E.
name: Chin, K.K.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1194-1199
description: Indium tin oxide (ITO) films deposited on glass substrate can be used as the transparent electrode for
thin film photovoltaics, such as CdTe-based thin film solar cells. The most widely used fabrication technique for ITO
films is magnetron sputtering directly from the ceramic target. While the preparation of ITO films is known for decade,
there is still lacking of consensus whether adding oxygen to the sputtering gas of Ar is beneficial to the film electrical
properties. Herein, we present a systematic experimental study comparing the properties of ITO films deposited under
pure Ar versus under Ar-O2 mixture with increasing O2 partial pressure. Our results of Hall measurements show that
adding more oxygen in the sputtering gas has negative influences on the electrical conductivity of ITO films. The origin
of these negative effects are discussed with a focus on the concentration of ionized impurities and the scattering of
grain barriers. We employed extensive XPS analysis to provide insight into the variation of oxygen vacancy
concentration as a function of sputtering O2 partial pressure. The ITO film microstructure was characterized using
XRD, STEM and high-magnification SEM analyses. Our results point to the oxygen vacancy concentration that dictates
the carrier concentration and thus the resistivity of magnetron sputtered ITO films.
Concentration-Dependent Domain Evolution in Reaction-Diffusion Systems
Creators: name: Krause, Andrew L.
name: Gaffney, Eamonn A.
name: Walker, Benjamin J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Cell Behavior (q-bio.CB)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Physical sciences
subject: FOS: Biological sciences
subject: 92C15 (primary) 35B36, 35K57 (secondary)

description: Pattern formation has been extensively studied in the context of evolving (time-dependent) domains in recent years, with domain growth implicated in ameliorating problems of pattern robustness and selection, in addition to more realistic modelling in developmental biology. Most work to date has considered prescribed domains evolving as given functions of time, but not the scenario of concentration-dependent dynamics, which is also highly relevant in a developmental setting. Here, we study such concentration-dependent domain evolution for reaction-diffusion systems to elucidate fundamental aspects of these more complex models. We pose a general form of one-dimensional domain evolution, and extend this to $N$-dimensional manifolds under mild constitutive assumptions in lieu of developing a full tissue-mechanical model. In the 1D case, we are able to extend linear stability analysis around homogeneous equilibria, though this is of limited utility in understanding complex pattern dynamics in fast growth regimes. We numerically demonstrate a variety of dynamical behaviours in 1D and 2D planar geometries, giving rise to several new phenomena, especially near regimes of critical bifurcation boundaries such as peak-splitting instabilities. For sufficiently fast growth and contraction, concentration-dependence can have an enormous impact on the nonlinear dynamics of the system both qualitatively and quantitatively. We highlight crucial differences between 1D evolution and higher dimensional models, explaining obstructions for linear analysis and underscoring the importance of careful constitutive choices in defining domain evolution in higher dimensions. We raise important questions in the modelling and analysis of biological systems, in addition to numerous mathematical questions that appear tractable in the one-dimensional setting, but are vastly more difficult for higher-dimensional models.
description: 22 pages, 12 figures
The Influence of Sodium in High Ga-Content Cu(In1-x,Gax)Se2 (CIGS) Solar Cells
Creators: name: Hao, X.
name: Chowdhury, K.T.
name: Sakurai, T.
name: Kamikawa-Shimizu, Y.
name: Ishizuka, S.
name: Yamada, A.
name: Shibata, H.
name: Akimoto, K.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1213-1215
description: This work compares a pair of CIGS solar cells with Ga content of 0.75 deposited on Na-incorporated
(soda lime glass, SLG) and Na-free (ceramic) substrates, respectively. The power conversion efficiency of the SLG
device is remarkably higher (11.06 %) than that of the ceramic one (4.44 %). The degraded open circuit voltage and
fill fact are the main reason of the poor performance for the ceramic device. The XRD results suggest a presence of
MoSe2 diffraction peak in SLG device and the formation of MoSe2 has already been proved to form an ohmic contact
at the CIGS/Mo interface and this might be a possible reason for the decreased series resistance for the SLG device.
Besides, the defect spectra indicate that the incorporation of Na will also affect the defect level and distributions in
CIGS thin films.
Special divisors on marked chains of cycles
Creators: name: Pflueger, Nathan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We completely describe all Brill-Noether loci on metric graphs consisting of a chain of g cycles with arbitrary edge lengths, generalizing work of Cools, Draisma, Payne, and Robeva. The structure of these loci is determined by displacement tableaux on rectangular partitions, which we define. More generally, we fix a marked point on the rightmost cycle, and completely analyze the loci of divisor classes with specified ramification at the marked point, classifying them using displacement tableaux. Our results give a tropical proof of the generalized Brill-Noether theorem for general marked curves, and serve as a foundation for the analysis of general algebraic curves of fixed gonality.
description: 25 pages. v2: various corrections and expository improvements
Variable-Range Hopping Versus Inter-Grain Tunneling in Cu2ZnSn(SxSe1-x)4 Thin-Films Prepared by Spray Pyrolysis
Creators: name: Lisunov, K.G.
name: Bruc, L.
name: Rusu, M.
name: Gurieva, G.
name: Guc, M.
name: Levcenko, S.
name: Dermenji, L.
name: Curmei, N.
name: Sherban, D.A.
name: Simashkevich, A.V.
name: Schorr, S.
name: Arushanov, E.K.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1186-1189
description: Thin Cu2ZnSn(SxSe1-x)4 films with x = 1.0 and 0.85 were prepared by the spray pyrolysis method
with subsequent annealing in the presence of elemental sulfur or selenium. The surface sensitive Raman
measurements indicated a high crystalline quality of all samples and absence of secondary phases. Small amount
of Cu2-xS secondary phase was detected from grazing incidence X-ray diffraction patterns (information depth of
about 500 nm). The resistivity,  (T), is governed by the Mott variable-range hopping conduction at high
temperatures, when the mean hopping length Rh (T) exceeds the mean distance between the acceptors, RA, but is
still smaller than the typical inter-grain distance, aig. However, with lowering the temperature the resistivity
becomes dominated by inter-grain tunneling, provided that Rh (T) > aig. The analysis of the  (T) function has
yielded the values of the acceptor concentration and the localization radius, with the evidence that all the
samples are characterized by a state far different from the metal-insulator transition. The radius of the mean size
grain as well as values of aig were in addition determined.
Effects of nuclear matter and composition in core-collapse supernovae and long-term proto-neutron star cooling
Creators: name: Sumiyoshi, Kohsuke
name: Furusawa, Shun
name: Nagakura, Hiroki
name: Harada, Akira
name: Togashi, Hajime
name: Nakazato, Ken'ichiro
name: Suzuki, Hideyuki
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the influence of hot and dense matter in core-collapse supernovae by adopting up-to-date nuclear equation of state (EOS) based on the microscopic nuclear many-body frameworks. We explore effects of EOS based on the Dirac Brueckner Hartree-Fock theory through comparisons with those based on the variational method. We also examine effects of the differences in the composition of nuclei and nucleons by using the same EOS by the variational method but employing two different treatments in computations of nuclear abundances. We perform numerical simulations of core-collapse supernovae adopting the three EOSs. We also perform numerical simulations of the long-term evolution over 70 s of the proto-neutron star cooling. We show that impacts by different modeling of composition are remarkable as in those by different treatments of uniform matter in the gravitational collapse, bounce, and shock propagation. The cooling of proto-neutron star and the resulting neutrino emission are also affected by the compositional difference even if the same treatment in computing uniform matter of EOS.
description: 33 pages, 23 figures, 1 table, accepted for publication in Progress of Theoretical and Experimental Physics (PTEP)
Identification of Loss Mechanisms in CIGS Micro-Cells for Concentrator Applications
Creators: name: Lotter, E.
name: Jackson, P.
name: Paetel, S.
name: Wischmann, W.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1156-1160
description: Recent results have proven the efficiency gain of micrometer-sized CIGS thin-film cells under medium
to high concentration. In this work, co-evaporated CIGS cells with sizes in the range of 0.04 mm² to 1 mm² were
investigated under white light illumination and concentrations up to 100 suns. The cells were isolated from finished
standard test cells from two different CIGS sources: the inline deposition system and the high-efficiency cell line at
ZSW.
High-efficiency cells with alkali post-deposition treatment were found to exhibit an internal series resistance with a
temperature behavior which indicates a built-in barrier. This barrier can limit the efficiency of micro-cells already at
moderate concentration factors.
The origin of shunting at the cell edges and its dependency on illumination intensity was studied for different
preparation techniques such as mechanical scribing, pico-second laser ablation, and chemical etching of the ZAO
layer. With the latter, very good edge passivation and efficiencies of up to 22.5% at 77 suns were achieved.
Dynamical systems analysis in $f(T,ϕ)$ gravity
Creators: name: Duchaniya, L. K.
name: Kadam, S. A.
name: Said, Jackson Levi
name: Mishra, B.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Teleparallel based cosmological models provide a description of gravity in which torsion is the mediator of gravitation. Several extensions have been made within the so-called Teleparallel equivalent of general relativity which is equivalent to general relativity at the level of the equations of motion where attempts are made to study the extensions of this form of gravity and to describe more general functions of the torsion scalar $T$. One of these extensions is $f(T,ϕ)$ gravity; $T$ and $ϕ$ respectively denote the torsion scalar and scalar field. In this work, the dynamical system analysis has been performed for this class of theories to obtain the cosmological behaviour of a number of models. Two models are presented here with some functional form of the torsion scalar and the critical points are obtained. For each critical point, the stability behaviour and the corresponding cosmology are shown. Through the graphical representation the equation of state parameter and the density parameters for matter-dominated, radiation-dominated and dark energy phase are also presented for both the models.
description: 15 pages, 4 figures
On the nature of the neutrino
Creators: name: Romero, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Physics (physics.gen-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Assuming that one neutrino type with definite mass is described by a massive Dirac field operator, it is shown that the physical one-particle states for particles and antiparticles can be rotated to each other, irrespective of their helicity. This result is used to prove that the neutrino must necessarily be a Majorana particle.
description: Errata to the published version: typos fixed in Table 1 and Eq.(28)
Elaboration of ZnO:Ga Thin Films by Spray Pyrolysis for Photovoltaic Applications
Creators: name: El Khalidi, Z.
name: Hartiti, B.
name: Fadili, S.
name: Lfakir, A.
name: Thevenin, P.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1161-1165
description: Zinc oxide Semiconductor is a promising material for optoelectronic applications. It is studied for the advantageous
properties such as good transparency, optical and electrical characteristics that makes it used as window layer in
photovoltaic cells. It can be elaborated using several preparation methods, besides introducing dopants to enhance its
optical and physical properties. Therefore, in the present work we have been interested in the synthesis of ZnO doped
gallium with different concentrations, using spray pyrolysis at 400°C. The characterization using XRD indicates that
the films exhibit polycrystalline structure, and a preferential orientation along (002) perpendicular to the substrate. The
electrical data using 4 point probe shows a resistivity of (25.10-4Ω.cm) for ZnO layer. The optical study showed a
transparent behavior of the films with a transmittance up to 90%. The refractive index n(), extinction coefficient, and
dielectric constants were also calculated. The lowest band gap energy is about (3.28 eV). The Urbach energy in
function of Ga % was studied to determine the disorder in the structure which is confirmed by the structural data. These
results indicate the conformity of the films to be potentially applicable as transparent layer in photovoltaic devices.
Collisional cooling of light ions by co-trapped heavy atoms
Creators: name: Dutta, Sourav
name: Sawant, Rahul
name: Rangwala, S. A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Chemical Physics (physics.chem-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We experimentally demonstrate cooling of trapped ions by collisions with co-trapped, higher mass neutral atoms. It is shown that the lighter $^{39}$K$^{+}$ ions, created by ionizing $^{39}$K atoms in a magneto-optical trap (MOT), when trapped in an ion trap and subsequently allowed to cool by collisions with ultracold, heavier $^{85}$Rb atoms in a MOT, exhibit a longer trap lifetime than without the localized $^{85}$Rb MOT atoms. A similar cooling of trapped $^{85}$Rb$^{+}$ ions by ultracold $^{133}$Cs atoms in a MOT is also demonstrated in a different experimental configuration to validate this mechanism of ion cooling by localized and centered ultracold neutral atoms. Our results suggest that cooling of ions by localized cold atoms holds for any mass ratio, thereby enabling studies on a wider class of atom-ion systems irrespective of their masses.
description: 5 pages (+ 5 pages of Supplementary Material), 4 figures (+ 4 figures in the Supplementary Material)
Indirect Laser Ablation of Cu(In, Ga)Se2-Layers by ns Pulses with a Wavelength of 1342 nm
Creators: name: Kaufmann, K.
name: Hagendorf, C.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1182-1185
description: Indirect laser ablation of thin layers from a substrate (lift-off) is a commonly known alternative to
direct ablation. Since energy deposition preferably takes place at the interface between thin film and substrate, the
thin film layer and especially the resulting scribe edges are less affected by laser irradiation. This reduces the
probability of thermally induced damage. For indirect laser ablation of Cu(In, Ga)Se2 layers the wavelength of 1342
nm is well suited, because CIGS layers are transparent regardless of their composition. We show that 10 ns pulses at
1342 nm are capable to remove CIGS layers from the underlying Mo substrate. Prior to ablation experiments the
mechanical interface strength of two different sample systems is analyzed with a scratch test method. It is shown that
low adhesion strength promotes an indirect ablation driven by mechanical effects without melting the CIGS material.
High interfacial adhesion strength leads to an evaporation driven lift-off process resulting in molten residuals at the
crater bottom.
On the Marked Length Spectrums of Generic Strictly Convex Billiard Tables
Creators: name: Huang, Guan
name: Kaloshin, Vadim
name: Sorrentino, Alfonso
Publisher: name: arXiv
Year: 2016
Subjects: subject: Dynamical Systems (math.DS)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: 35P30, 37D50, 37E40, 37J50, 35P05, 37D05, 37J45

description: In this paper we show that for a generic strictly convex domain, one can recover the eigendata corresponding to Aubry-Mather periodic orbits of the induced billiard map, from the (maximal) marked length spectrum of the domain.
description: 25 pages, 3 figures. (This version has been revised in the light of the referee's report). arXiv admin note: text overlap with arXiv:1309.1008
Effects of Stacking Sequences in the Formation of CZTS Thin Film Using Electron Beam Evaporation
Creators: name: Pidugu Kesavan, P.K.
name: Chaudhari, S.
name: Dey, S.R.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1170-1174
description: This study investigated the influence of stacking sequences in the formation of deleterious secondary
phases which has degrading effects on the performance of Cu2ZnSnS4 (CZTS) thin film solar cells. Various stacking
of absorber layer precursors for e.g. Zn/Sn/Cu, Sn/Zn/Cu, Cu/Zn/Sn/Cu and Cu/Sn/Zn/Cu are prepared on glass
substrates without heating using electron beam evaporation of elemental metallic precursors. Interdiffusion of metals
is confirmed from the XRD results. Further, the precursor films are sulfurized at 500°C for 1 hr in the presence of
elemental sulfur powder having N2 as the carrier gas. The effect of ramping rates on the formation of secondary phases
are investigated using XRD and Raman spectroscopy. It is found that precursor stacking sequence of Sn/Zn/Cu
sulfurized at a rate of 1°C/min and Cu/Sn/Zn/Cu at a sulfurization ramping rate of 1°C/min are the optimum condition
for the formation of phase pure CZTS thin films.
Fermi GBM Observations of LIGO Gravitational Wave event GW150914
Creators: name: Connaughton, V.
name: Burns, E.
name: Goldstein, A.
name: Blackburn, L.
name: Briggs, M. S.
name: Zhang, B. -B.
name: Camp, J.
name: Christensen, N.
name: Hui, C. M.
name: Jenke, P.
name: Littenberg, T.
name: McEnery, J. E.
name: Racusin, J.
name: Shawhan, P.
name: Singer, L.
name: Veitch, J.
name: Wilson-Hodge, C. A.
name: Bhat, P. N.
name: Bissaldi, E.
name: Cleveland, W.
name: Fitzpatrick, G.
name: Giles, M. M.
name: Gibby, M. H.
name: von Kienlin, A.
name: Kippen, R. M.
name: McBreen, S.
name: Mailyan, B.
name: Meegan, C. A.
name: Paciesas, W. S.
name: Preece, R. D.
name: Roberts, O.
name: Sparke, L.
name: Stanbro, M.
name: Toelge, K.
name: Veres, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: With an instantaneous view of 70% of the sky, the Fermi Gamma-ray Burst Monitor (GBM) is an excellent partner in the search for electromagnetic counterparts to gravitational wave (GW) events. GBM observations at the time of the Laser Interferometer Gravitational-wave Observatory (LIGO) event GW150914 reveal the presence of a weak transient above 50 keV, 0.4~s after the GW event, with a false alarm probability of 0.0022 (2.9$σ$). This weak transient lasting 1 s was not detected by any other instrument and does not appear connected with other previously known astrophysical, solar, terrestrial, or magnetospheric activity. Its localization is ill-constrained but consistent with the direction of GW150914. The duration and spectrum of the transient event are consistent with a weak short Gamma-Ray Burst arriving at a large angle to the direction in which Fermi was pointing, where the GBM detector response is not optimal. If the GBM transient is associated with GW150914, this electromagnetic signal from a stellar mass black hole binary merger is unexpected. We calculate a luminosity in hard X-ray emission between 1~keV and 10~MeV of $1.8^{+1.5}_{-1.0} \times 10^{49}$~erg~s$^{-1}$. Future joint observations of GW events by LIGO/Virgo and Fermi GBM could reveal whether the weak transient reported here is a plausible counterpart to GW150914 or a chance coincidence, and will further probe the connection between compact binary mergers and short Gamma-Ray Bursts.
description: Accepted for publication in ApJL
An Investigation of Pre-Conditioning Routines for Accurate Efficiency Measurements of Perovskite Solar Cells
Creators: name: Dunbar, R.B.
name: Moustafa, W.
name: Duffy, N.
name: Duck, B.
name: Anderson, K.F.
name: Jones, T.W.
name: Fell, C.J.
name: Wilson, G.J.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
Perovskite, Organic and Hybrid devices

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1126-1129
description: Despite the rapid rise in efficiency reported for research-scale perovskite solar cells, significant
measurement challenges remain. A key challenge is the tendency for perovskite solar cells to respond slowly (on
timescales of seconds to minutes) to changes in voltage bias and irradiance, which typically leads to a dependence of
measurement results on cell history and measurement approach. Here, we investigate pre-conditioning treatments,
which can be applied to prevent transient effects being mistaken for voltage-dependence during measurement of
current-voltage curves. We find the measurement history of a device can significantly influence transient current
characteristics when the device is transitioned from being in the dark to being illuminated. For the device structure
investigated in this work, light-soaking periods of 5-10 minutes can be sufficient to return the device to the
illuminated steady-state provided the device was light-soaked for 10 minutes no more than 45 minutes previously.
Otherwise, longer additional light-soaking periods are required. This is important information for efficiency
measurement of devices subject to performance degradation on these timescales. If sufficiently long dark rest periods
are allowed prior to measurement, distinct dips are readily observable in current transients between 0 and 100
seconds after illumination commences.
Reverse-Voltage Bias Induced Shunt Formation in Cu(In,Ga)Se2 Thin Film Solar Cells: an Approach with Three-Dimensional Electro-Thermal Simulations
Creators: name: Richter, M.
name: Neerken, J.
name: Parisi, J.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1116-1119
description: By partial shading of thin-film solar panels a high reverse voltage drops across shaded solar cells.
These solar cells may be driven into breakdown, which causes in the worst case severe damage to the cell. With dark
lock-in thermography the damaged sites are then visible as shunt signals observed. An important issue to prevent
cells from damaging is to understand the reasons why a specific site tends to get damaged at reverse bias and how it
might be identified before the damage occurred. We developed a three-dimensional simulation structure of a single
cell to perform numerical electro-thermal simulations and calibrated the current-voltage and thermal characteristics to
a sample we extracted from a module. We studied the thermal signal and corresponding efficiency loss of the device
when different types of defects are present. Furthermore, we simulated at the conditions at which real solar cells get
damaged. We found that these conditions are not sufficient to generate enough heat at already existing shunts to cause
additional damage. However, local recombination sites cause high electric fields at reverse bias, which increase the
probability of breakdown processes as avalanche breakdown or band-to-band tunneling.
Cadmium Sulfide Films Grown by Photochemical Deposition and Their Application in CIGS Solar Cells
Creators: name: Zhang, J.
name: Xiaojie, Y.
name: Lexi, S.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1141-1143
description: Uniform Cadmium Sulfide (CdS) thin films have been deposited on CIGS thin films as buffer layers
by photochemical deposition (PCD) technique. The CdS film is formed and deposited only in the illuminated region
of the substrate where UV light is focused. Therefore, the thickness of deposited film is easily controlled by turning
on/off the illumination or by changing the illumination intensity. The films were characterized by X-ray
diffraction(XRD), Raman spectroscopy and optical transmission spectroscopy. The performances of the CIGS-based
solar cells fabricated using PCD-CdS as buffer layers were compared to the standard CdS solar cells deposited by
chemical bath deposition (CBD). Our results showed an efficiency of 7.5% for the CIGS solar cells with PCD-CdS
buffer layers.
Nanosecond Photoemission near the Potential Barrier of a Schottky Emitter
Creators: name: Reynolds, Joshua L.
name: Israel, Yonatan
name: Bowman, Adam J.
name: Klopfer, Brannon B.
name: Kasevich, Mark A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nanosecond electron pulses are appealing for ultrafast imaging and electron gating applications, where tunable currents and narrow energy spreads are desirable. Here, we demonstrate photoemission from a Schottky emitter triggered by nanosecond laser pulses and use a dispersive magnetic prism array to image the electron energy distributions. Using photon energies optimally tuned to the emission potential barrier, we generate pulses containing over 10$^5$ electrons with energy spreads below 1 eV with a prompt, single-photon emission process. These results are consistent with theoretical models of laser-triggered electron emission and energetic broadening during propagation and can be widely implemented.
Lie algebroids as $L_\infty$ spaces
Creators: name: Grady, Ryan E.
name: Gwilliam, Owen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: Algebraic Geometry (math.AG)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics

description: In this paper, we relate Lie algebroids to Costello's version of derived geometry. For instance, we show that each Lie algebroid $L$-and the natural generalization to dg Lie algebroids-provides an (essentially unique) $L_\infty$ space. More precisely, we construct a faithful functor from the category of Lie algebroids to the category of $L_\infty$ spaces. Then we show that for each Lie algebroid $L$, there is a fully faithful functor from the category of representations up to homotopy of $L$ to the category of vector bundles over the associated $L_\infty$ space. Indeed, this functor sends the adjoint complex of $L$ to the tangent bundle of the $L_\infty$ space. Finally, we show that a shifted-symplectic structure on a dg Lie algebroid $L$ produces a shifted-symplectic structure on the associated $L_\infty$ space.
description: 46 pages, final version
The Impact of Oxygen Inlet during Close-Spaced Sublimation Process on the as-Deposited and Chlorine Treated Microstructure of CdTe Layers
Creators: name: Hirsch, D.
name: Zywitzki, O.
name: Modes, T.
name: Morgner, H.
name: Späth, B.
name: Siepchen, B.
name: Drost, C.
name: Kraft, C.
name: Krishnakumar, V.
name: Metzner, C.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
CdTe, CIS and Related Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1072-1075
description: In this study CdTe thin films were deposited by close-spaced sublimation (CSS) in an oxygen
ambient and the influence of oxygen on the properties of as-deposited and chlorine activated CdTe microstructures
were investigated. FE-SEM imaging of ion-polished cross sections of the as-deposited CdTe-layers revealed a
significant change from a block-like to a columnar microstructure with increasing oxygen concentration in the gas
flux. After the chlorine activation step at 440 °C the oxygen free sample shows a strong sulfur diffusion whereas
samples with low oxygen inlet show a suppressed diffusion. Due to the enlarged amount of grain boundaries in the
as-deposited microstructure the sulfur diffusion became stronger again with increasing oxygen concentration.
Is there evidence for CIDER in the Universe?
Creators: name: Barros, Bruno J.
name: Castelão, Diogo
name: da Fonseca, Vitor
name: Barreiro, Tiago
name: Nunes, Nelson J.
name: Tereno, Ismael
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work we analyze the full linear behaviour of the constrained interacting dark energy (CIDER) model, which is a conformally coupled quintessence model tailored to mimic a $Λ$CDM expansion. We compute the matter and temperature anisotropies power spectra and test the model against recent observational data. We shed light on some particular subtleties of the background behaviour that were not fully captured in previous works, and study the physics of the linear cosmological observables. One novelty found was that matter perturbations are enhanced at large scales when compared with the ones of the standard $Λ$CDM. The reason and impact of this trend on the cosmological observables and on the physics of the early Universe are considered. We find that the introduction of the coupling parameter alleviates the $σ_8$ tension between early and late time probes although Planck data favours the $Λ$CDM limit of the model.
description: 13 pages, 11 figures, 1 table. V2: Matches published version
A Gromov-Hausdorff Distance between von Neumann Algebras and an Application to Free Quantum Fields
Creators: name: Guido, D.
name: Marotta, N.
name: Morsella, G.
name: Suriano, L.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Operator Algebras (math.OA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 46Lxx, 81T05

description: A distance between von Neumann algebras is introduced, depending on a further norm inducing the $w^*$-topology on bounded sets. Such notion is related both with the Gromov-Hausdorff distance for quantum metric spaces of Rieffel and with the Effros-Marechal topology on the von Neumann algebras acting on a Hilbert space. This construction is tested on the local algebras of free quantum fields endowed with norms related with the Buchholz-Wichmann nuclearity condition, showing the continuity of such algebras w.r.t. the mass parameter.
description: 22 pages, no figures. To apper in the Journal of Functional Analysis
Analysis of Carrier Lifetime in Liquid-Phase Crystallized Silicon on Glass
Creators: name: Vetter, M.
name: Gawlik, A.
name: Plentz, J.
name: Andrä, G.
Publisher: name: WIP
Year: 2016
Subjects: Thin Film Solar Cells and Modules
Silicon-based Thin Film Solar Cells and Modules

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 1100-1103
description: Liquid-phase crystallized silicon on glass (LPCSG) presents a promising material to fabricate high
quality silicon thin films on glass, e.g. for solar cells and modules. To achieve a high electronic material quality after
the crystallization process on glass, first barrier layers (BL) and then an amorphous silicon layer are deposited on the
glass followed by crystallization with a line focus laser beam. In this paper we use injection level dependent lifetime
data generated by the quasi steady-state photoconductance decay method (QSSPC) to characterize LPCSG absorbers.
This contactless method allows a determination of the LPCSG absorber quality already at an early stage of solar cell
fabrication, and provides a monitoring of the absorber quality during solar cell fabrication steps. So far, we found
minority carrier lifetimes higher than 500 ns (e.g. n-type absorber with ND = 4x1016cm-3) indicating a surface
recombination velocity SBL < 1600 cm/s at the BL-Si interface and an effective diffusion length Leff > 20 mm in an 8
mm thick absorber.