TY - CHAP A1 - Burger, Sven A1 - Gutsche, Philipp A1 - Hammerschmidt, Martin A1 - Herrmann, Sven A1 - Pomplun, Jan A1 - Schmidt, Frank A1 - Wohlfeil, Benjamin A1 - Zschiedrich, Lin T1 - Hp-finite-elements for simulating electromagnetic fields in optical devices with rough textures T2 - Proc. SPIE Y1 - 2015 U6 - https://doi.org/10.1117/12.2190119 VL - 9630 SP - 96300S ER - TY - GEN A1 - Hammerschmidt, Martin A1 - Herrmann, Sven A1 - Pomplun, Jan A1 - Zschiedrich, Lin A1 - Burger, Sven A1 - Schmidt, Frank T1 - Reduced basis method for Maxwell's equations with resonance phenomena T2 - Proc. SPIE N2 - Rigorous optical simulations of 3-dimensional nano-photonic structures are an important tool in the analysis and optimization of scattering properties of nano-photonic devices or parameter reconstruction. To construct geometrically accurate models of complex structured nano-photonic devices the finite element method (FEM) is ideally suited due to its flexibility in the geometrical modeling and superior convergence properties. Reduced order models such as the reduced basis method (RBM) allow to construct self-adaptive, error-controlled, very low dimensional approximations for input-output relationships which can be evaluated orders of magnitude faster than the full model. This is advantageous in applications requiring the solution of Maxwell's equations for multiple parameters or a single parameter but in real time. We present a reduced basis method for 3D Maxwell's equations based on the finite element method which allows variations of geometric as well as material and frequency parameters. We demonstrate accuracy and efficiency of the method for a light scattering problem exhibiting a resonance in the electric field. T3 - ZIB-Report - 15-37 KW - reduced basis method KW - finite element method KW - maxwell equation KW - photonic crystal KW - nano-photonics Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-55687 SN - 1438-0064 VL - 9630 SP - 96300R ER - TY - JOUR A1 - Becker, Christiane A1 - Wyss, Philippe A1 - Eisenhauer, David A1 - Probst, Jürgen A1 - Preidel, Veit A1 - Hammerschmidt, Martin A1 - Burger, Sven T1 - 5 x 5 cm2 silicon photonic crystal slabs on glass and plastic foil exhibiting broadband absorption and high-intensity near-fields JF - Sci. Rep. Y1 - 2014 U6 - https://doi.org/10.1038/srep05886 VL - 4 SP - 5886 ER - TY - GEN A1 - Hammerschmidt, Martin A1 - Döpking, Sandra A1 - Burger, Sven A1 - Matera, Sebastian T1 - Field Heterogeneities and their Impact on Photocatalysis: Combining optical and kinetic Monte Carlo Simulations on the Nanoscale N2 - Gaining insights into the working principles of photocatalysts on an atomic scale is a challenging task. The obviously high complexity of the reaction mechanism involving photo-excited electrons and holes is one reason. Another complicating aspect is that the electromagnetic field, driving photocatalysis, is not homogeneous on a nanoscale level for particle based catalysts as it is influenced by the particle’s shape and size. We present a simple model, inspired by the CO2 reduction on titania anatase, which addresses the impact of these heterogeneities on the photocatalytic kinetics by combining kinetic Monte Carlo with electromagnetic wave simulations. We find that average activity and especially efficiency might differ significantly between different particles. Moreover, we find sizable variation of the catalytic activity on a single facet of a nanocrystal. Besides this quantitative heterogeneity, the coverage situation in general changes laterally on this facet and we observe a concomitant change of the rate-determining steps. This heterogeneity on all levels of photocatalytic activity is masked in experimental studies, where only the spatially averaged activity can be addressed. Microkinetic models based on experimental findings might therefore not represent the true micro- scopic behavior, and mechanistic conclusion drawn from these need to be handled with care. T3 - ZIB-Report - 17-20 Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-63690 SN - 1438-0064 ER - TY - CHAP A1 - Jäger, Klaus A1 - Köppel, Grit A1 - Hammerschmidt, Martin A1 - Burger, Sven A1 - Becker, Christiane T1 - Accurate optical simulations of periodic nanostructures on a thick glass substrate T2 - 29th Workshop on Quantum Solar Energy Conversion - (QUANTSOL) Y1 - 2017 ER - TY - GEN A1 - Hammerschmidt, Martin A1 - Weiser, Martin A1 - Santiago, Xavier Garcia A1 - Zschiedrich, Lin A1 - Bodermann, Bernd A1 - Burger, Sven T1 - Quantifying parameter uncertainties in optical scatterometry using Bayesian inversion N2 - We present a Newton-like method to solve inverse problems and to quantify parameter uncertainties. We apply the method to parameter reconstruction in optical scatterometry, where we take into account a priori information and measurement uncertainties using a Bayesian approach. Further, we discuss the influence of numerical accuracy on the reconstruction result. T3 - ZIB-Report - 17-37 KW - computational metrology KW - optical metrology KW - computational lithography KW - nanolithography KW - finite- element methods KW - nanooptics Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-64704 SN - 1438-0064 ER - TY - CHAP A1 - Mangalgiri, Gauri A1 - Šiškins, Makars A1 - Arslanova, Alina A1 - Hammerschmidt, Martin A1 - Manley, Phillip A1 - Riedel, Wiebke A1 - Schmid, Martina T1 - Highly Transmittive Broadband Dielectric Nanoholes T2 - CLEO Y1 - 2017 U6 - https://doi.org/10.1364/CLEO_AT.2017.JTu5A.117 SP - JTu5A.117 ER - TY - JOUR A1 - Jäger, Klaus A1 - Köppel, Grit A1 - Eisenhauer, David A1 - Chen, Duote A1 - Hammerschmidt, Martin A1 - Burger, Sven A1 - Becker, Christiane T1 - Optical simulations of advanced light management for liquid-phase crystallized silicon thin-film solar cells JF - Proc. SPIE Y1 - 2017 U6 - https://doi.org/10.1117/12.2273994 VL - 10356 SP - 103560F ER - TY - JOUR A1 - Barth, Carlo A1 - Roder, Sebastian A1 - Brodoceanu, Daniel A1 - Kraus, Tobias A1 - Hammerschmidt, Martin A1 - Burger, Sven A1 - Becker, Christiane T1 - Increased fluorescence of PbS quantum dots in photonic crystals by excitation enhancement JF - Appl. Phys. Lett. Y1 - 2017 U6 - https://doi.org/10.1063/1.4995229 VL - 111 SP - 031111 ER - TY - JOUR A1 - Hammerschmidt, Martin A1 - Weiser, Martin A1 - Santiago, Xavier Garcia A1 - Zschiedrich, Lin A1 - Bodermann, Bernd A1 - Burger, Sven T1 - Quantifying parameter uncertainties in optical scatterometry using Bayesian inversion JF - Proc. SPIE Y1 - 2017 U6 - https://doi.org/10.1117/12.2270596 VL - 10330 SP - 1033004 ER - TY - CHAP A1 - Lockau, Daniel A1 - Hammerschmidt, Martin A1 - Haschke, Jan A1 - Blome, Mark A1 - Ruske, Florian A1 - Schmidt, Frank A1 - Rech, Bernd T1 - A comparison of scattering and non-scattering anti-reflection designs for back contacted polycrystalline thin film silicon solar cells in superstrate configuration T2 - Proc. SPIE Y1 - 2014 U6 - https://doi.org/10.1117/12.2052362 VL - 9140 SP - 914006 ER - TY - GEN A1 - Hammerschmidt, Martin A1 - Pomplun, Jan A1 - Burger, Sven A1 - Schmidt, Frank T1 - Adaptive sampling strategies for efficient parameter scans in nano-photonic device simulations N2 - Rigorous optical simulations are an important tool in optimizing scattering properties of nano-photonic devices and are used, for example, in solar cell optimization. The finite element method (FEM) yields rigorous, time-harmonic, high accuracy solutions of the full 3D vectorial Maxwell's equations [1] and furthermore allows for great flexibility and accuracy in the geometrical modeling of these often complex shaped 3D nano-structures. A major drawback of frequency domain methods is the limitation of single frequency evaluations. For example the accurate computation of the short circuit current density of an amorphous silicon / micro-crystalline multi-junction thin film solar cell may require the solution of Maxwell's equations for over a hundred different wavelengths if an equidistant sampling strategy is employed. Also in optical metrology, wavelength scans are frequently used to reconstruct unknown geometrical and material properties of optical systems numerically from measured scatterometric data. In our contribution we present several adaptive numerical integration and sampling routines and study their efficiency in the context of the determination of generation rate profiles of solar cells. We show that these strategies lead to a reduction in the computational effort without loss of accuracy. We discuss the employment of tangential information in a Hermite interpolation scheme to achieve similar accuracy on coarser grids. We explore the usability of these strategies for scatterometry and solar cell simulations. T3 - ZIB-Report - 14-20 KW - finite element method KW - optical simulations KW - adaptive sampling KW - optical metrology KW - parameter scans KW - solar cells Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-50395 SN - 1438-0064 ER - TY - GEN A1 - Hammerschmidt, Martin A1 - Lockau, Daniel A1 - Zschiedrich, Lin A1 - Schmidt, Frank T1 - Optical modelling of incoherent substrate light-trapping in silicon thin film multi-junction solar cells with finite elements and domain decomposition N2 - In many experimentally realized applications, e.g. photonic crystals, solar cells and light-emitting diodes, nano-photonic systems are coupled to a thick substrate layer, which in certain cases has to be included as a part of the optical system. The finite element method (FEM) yields rigorous, high accuracy solutions of full 3D vectorial Maxwell's equations [1] and allows for great flexibility and accuracy in the geometrical modelling. Time-harmonic FEM solvers have been combined with Fourier methods in domain decomposition algorithms to compute coherent solutions of these coupled system. [2,3] The basic idea of a domain decomposition approach lies in a decomposition of the domain into smaller subdomains, separate calculations of the solutions and coupling of these solutions on adjacent subdomains. In experiments light sources are often not perfectly monochromatic and hence a comparision to simulation results might only be justified if the simulation results, which include interference patterns in the substrate, are spectrally averaged. In this contribution we present a scattering matrix domain decomposition algorithm for Maxwell's equations based on FEM. We study its convergence and advantages in the context of optical simulations of silicon thin film multi-junction solar cells. This allows for substrate light-trapping to be included in optical simulations and leads to a more realistic estimation of light path enhancement factors in thin-film devices near the band edge. T3 - ZIB-Report - 14-21 KW - finite element method KW - rigorous optical modeling KW - domain decomposition KW - multi-junction solar cells KW - thin-film silicon solar cells KW - incoherent layers KW - incoherent light-trapping Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-50410 SN - 1438-0064 ER -