@inproceedings{BarthRoderBrodoceanuetal.2016, author = {Barth, Carlo and Roder, Sebastian and Brodoceanu, Daniel and Kraus, Tobias and Burger, Sven and Hammerschmidt, Martin and Schmidt, Frank and Becker, Christiane}, title = {Increased fluorescence of PbS quantum dots on photonic crystal slab structures}, booktitle = {Proc. Europ. Opt. Soc. Ann. Meet. 2016 (EOSAM)}, isbn = {978-1-5108-4796-5}, pages = {181}, year = {2016}, language = {en} } @inproceedings{HammerschmidtBarthBurgeretal.2016, author = {Hammerschmidt, Martin and Barth, Carlo and Burger, Sven and Becker, Christiane and Schmidt, Frank}, title = {Determining 2D photonic crystal geometries from reflectance spectra with a reduced basis method}, booktitle = {Proc. Europ. Opt. Soc. Ann. Meet. 2016 (EOSAM)}, isbn = {978-1-5108-4796-5}, pages = {281}, year = {2016}, language = {en} } @inproceedings{JaegerManleyEisenhaueretal.2018, author = {J{\"a}ger, Klaus and Manley, Phillip and Eisenhauer, David and Tockhorn, Philipp and Sutter, Johannes and Hammerschmidt, Martin and Burger, Sven and Albrecht, Steve and Becker, Christiane}, title = {Light management with sinusoidal nanotextures}, booktitle = {Light, Energy and the Environment 2018}, doi = {10.1364/OSE.2018.OT5C.5}, pages = {OT5C.5}, year = {2018}, language = {en} } @inproceedings{JaegerHammerschmidtKoeppeletal.2016, author = {J{\"a}ger, Klaus and Hammerschmidt, Martin and K{\"o}ppel, Grit and Burger, Sven and Becker, Christiane}, title = {On Accurate Simulations of Thin-Film Solar Cells With a Thick Glass Superstrate}, booktitle = {Light, Energy and the Environment 2016}, doi = {10.1364/PV.2016.PM3B.5}, pages = {PM3B.5}, year = {2016}, language = {en} } @inproceedings{JaegerBarthHammerschmidtetal.2016, author = {J{\"a}ger, Klaus and Barth, Carlo and Hammerschmidt, Martin and Herrmann, Sven and Burger, Sven and Schmidt, Frank and Becker, Christiane}, title = {Sinusoidal Nanotextures for Enhanced Light Management in Thin-Film Solar Cells}, booktitle = {28th Workshop on Quantum Solar Energy Conversion - (QUANTSOL)}, editor = {European Society for Quantum Solar Energy Conversion,}, year = {2016}, language = {en} } @article{BarthProbstHerrmannetal.2016, author = {Barth, Carlo and Probst, J{\"u}rgen and Herrmann, Sven and Hammerschmidt, Martin and Becker, Christiane}, title = {Numerical characterization of symmetry properties for photonic crystals with hexagonal lattice}, volume = {9885}, journal = {Proc. SPIE}, doi = {10.1117/12.2227094}, pages = {988506}, year = {2016}, abstract = {We present a numerical method to characterize the symmetry properties of photonic crystal (PhC) modes based on field distributions, which themselves can be obtained numerically. These properties can be used to forecast specific features of the optical response of such systems, e.g. which modes are allowed to couple to external radiation fields. We use 2D PhCs with a hexagonal lattice of holes in dielectric as an example and apply our technique to reproduce results from analytical considerations. Further, the method is extended to fully vectorial problems in view of 3D PhCs and PhC slabs, its functionality is demonstrated using test cases and, finally, we provide an efficient implementation. The technique can thus readily be applied to output data of all band structure computation methods or even be embedded - gaining additional information about the mode symmetry.}, language = {en} } @article{JaegerKoeppelBarthetal.2016, author = {J{\"a}ger, Klaus and K{\"o}ppel, Grit and Barth, Carlo and Hammerschmidt, Martin and Herrmann, Sven and Burger, Sven and Schmidt, Frank and Becker, Christiane}, title = {Sinusoidal gratings for optimized light management in c-Si thin-film solar cells}, volume = {9898}, journal = {Proc. SPIE}, doi = {10.1117/12.2225459}, pages = {989808}, year = {2016}, language = {en} } @phdthesis{Hammerschmidt2016, author = {Hammerschmidt, Martin}, title = {Optical simulation of complex nanostructured solar cells with a reduced basis method}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:188-fudissthesis000000102429-1}, pages = {XX, 169}, year = {2016}, abstract = {Simulations of optical processes and complex nanostructured devices have become omnipresent in recent years in several fields of current research and industrial applications, not limited to the field of photovoltaics. Devices or processes are optimized with respect to a certain objective where the underlying physical processes are described by partial differential equations. In photovoltaics and photonics electromagnetic fields are investigated which are governed by Maxwell's equations. In this thesis a reduced basis method for the solution of the parameter dependent electromagnetic scattering problem with arbitrary parameters is developed. The method is developed with the specific challenges arising in optical simulations of thin-film silicon solar cells in mind. These are large in domain size and have a complex three-dimensional structure, making optimization tasks infeasible if high-accuracy of the electromagnetic field solution is required. The application of the empirical interpolation methods allows to expand an arbitrary parameter dependence affinely. Thus not only geometries, but also material tensors and source fields can be parameterized. Additionally, the required non-linear post-processing steps of the electromagnetic field to derive energy fluxes or volume absorption are addressed. The reduced basis method allows to reduce the computational costs by orders of magnitude compared to efficient finite element solvers. In addition, an efficient tailored domain decomposition algorithm is presented to model incoherent layers or illuminations in optical systems efficiently. This is of particular interest for solar cells in superstrate configuration where the absorber is illuminated through a glass substrate. The developed methods are employed in application examples taken from collaborations with experimentalists active in the joint lab "BerOSE" (Berlin Joint Lab for Optical Simulations for Energy Research). The optical model of a thin-film silicon multi-junction with incoherent light-trapping is characterized in great detail. The computational gains through hybrid, hp adaptive finite elements are studied and the incoherent domain decomposition algorithm is applied to model a more realistic light-trapping by the glass substrate. The numerical examples of a hexagonal nano-hole array and multi-junction silicon solar cell with a tunable intermediate reflector layer show that the reduced basis method is well suited as a forward solver for modeling and optimization tasks arising in photovoltaics and photonics. Reduced models for illumination and geometric parameters are built providing up to five orders of magnitude savings in computational costs. Resonance phenomena present in the nano-hole array example are detected and the model adapts itself automatically.}, language = {en} } @article{JaegerManleyChenetal.2018, author = {J{\"a}ger, Klaus and Manley, Phillip and Chen, Duote and Tockhorn, Philipp and Eisenhauer, David and K{\"o}ppel, Grit and Hammerschmidt, Martin and Burger, Sven and Albrecht, Steve and Becker, Christiane}, title = {Antireflective nanotextures for monolithic perovskite-silicon tandem solar cells}, volume = {10688}, journal = {Proc. SPIE}, arxiv = {http://arxiv.org/abs/1805.10152}, doi = {10.1117/12.2306142}, pages = {106880A}, year = {2018}, language = {en} } @article{HammerschmidtDoepkingBurgeretal.2020, author = {Hammerschmidt, Martin and D{\"o}pking, Sandra and Burger, Sven and Matera, Sebastian}, title = {Field Heterogeneities and Their Impact on Photocatalysis: Combining Optical and Kinetic Monte Carlo Simulations on the Nanoscale}, volume = {124}, journal = {J. Phys. Chem. C}, doi = {10.1021/acs.jpcc.9b11469}, pages = {3177}, year = {2020}, language = {en} } @article{ManleyWaldeHagedornetal.2020, author = {Manley, Phillip and Walde, Sebastian and Hagedorn, Sylvia and Hammerschmidt, Martin and Burger, Sven and Becker, Christiane}, title = {Nanopatterned Sapphire Substrates in Deep-UV LEDs: Is there an Optical Benefit?}, volume = {28}, journal = {Opt. Express}, doi = {10.1364/OE.379438}, pages = {3619}, year = {2020}, language = {en} } @inproceedings{ManleyHammerschmidtBurgeretal.2019, author = {Manley, Phillip and Hammerschmidt, Martin and Burger, Sven and Becker, Christiane}, title = {Nanophotonic Enhancement of Light Out-Coupling for Deep-UV LEDs}, booktitle = {The 10th International Conference on Metamaterials, Photonic Crystals and Plasmonics (META 2019)}, editor = {Zhoudi, Said and Topa, Antonio}, issn = {2429-1390}, pages = {745}, year = {2019}, language = {en} } @article{ChenManleyTockhornetal.2018, author = {Chen, Duote and Manley, Phillip and Tockhorn, Philipp and Eisenhauer, David and K{\"o}ppel, Grit and Hammerschmidt, Martin and Burger, Sven and Albrecht, Steve and Becker, Christiane and J{\"a}ger, Klaus}, title = {Nanophotonic Light Management for Perovskite-Silicon Tandem Solar Cells}, volume = {8}, journal = {J. Photonics Energy}, arxiv = {http://arxiv.org/abs/1801.07252}, doi = {10.1117/1.JPE.8.022601}, pages = {022601}, year = {2018}, language = {en} } @misc{HammerschmidtDoepkingBurgeretal.2017, author = {Hammerschmidt, Martin and D{\"o}pking, Sandra and Burger, Sven and Matera, Sebastian}, title = {Field Heterogeneities and their Impact on Photocatalysis: Combining optical and kinetic Monte Carlo Simulations on the Nanoscale}, issn = {1438-0064}, doi = {10.1021/acs.jpcc.9b11469}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-63690}, year = {2017}, abstract = {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.}, language = {en} } @inproceedings{JaegerKoeppelHammerschmidtetal.2017, author = {J{\"a}ger, Klaus and K{\"o}ppel, Grit and Hammerschmidt, Martin and Burger, Sven and Becker, Christiane}, title = {Accurate optical simulations of periodic nanostructures on a thick glass substrate}, booktitle = {29th Workshop on Quantum Solar Energy Conversion - (QUANTSOL)}, year = {2017}, language = {en} } @inproceedings{MangalgiriŠiškinsArslanovaetal.2017, author = {Mangalgiri, Gauri and Šiškins, Makars and Arslanova, Alina and Hammerschmidt, Martin and Manley, Phillip and Riedel, Wiebke and Schmid, Martina}, title = {Highly Transmittive Broadband Dielectric Nanoholes}, booktitle = {CLEO}, doi = {10.1364/CLEO_AT.2017.JTu5A.117}, pages = {JTu5A.117}, year = {2017}, language = {en} } @article{JaegerKoeppelEisenhaueretal.2017, author = {J{\"a}ger, Klaus and K{\"o}ppel, Grit and Eisenhauer, David and Chen, Duote and Hammerschmidt, Martin and Burger, Sven and Becker, Christiane}, title = {Optical simulations of advanced light management for liquid-phase crystallized silicon thin-film solar cells}, volume = {10356}, journal = {Proc. SPIE}, doi = {10.1117/12.2273994}, pages = {103560F}, year = {2017}, language = {en} } @article{BarthRoderBrodoceanuetal.2017, author = {Barth, Carlo and Roder, Sebastian and Brodoceanu, Daniel and Kraus, Tobias and Hammerschmidt, Martin and Burger, Sven and Becker, Christiane}, title = {Increased fluorescence of PbS quantum dots in photonic crystals by excitation enhancement}, volume = {111}, journal = {Appl. Phys. Lett.}, arxiv = {http://arxiv.org/abs/1708.06566}, doi = {10.1063/1.4995229}, pages = {031111}, year = {2017}, language = {en} } @inproceedings{JaegerBarthHammerschmidtetal.2015, author = {J{\"a}ger, Klaus and Barth, Carlo and Hammerschmidt, Martin and Herrmann, Sven and Burger, Sven and Schmidt, Frank and Becker, Christiane}, title = {Sinusoidal Nanotextures for Coupling Light into c-Si Thin-Film Solar Cells}, booktitle = {Light, Energy and the Environement 2015}, doi = {10.1364/PV.2015.PTu4B.3}, pages = {PTu4B.3}, year = {2015}, language = {en} } @inproceedings{BarthJaegerBurgeretal.2015, author = {Barth, Carlo and J{\"a}ger, Klaus and Burger, Sven and Hammerschmidt, Martin and Schmidt, Frank and Becker, Christiane}, title = {Design of Photonic Crystals with Near-Surface Field Enhancement}, booktitle = {Light, Energy and the Environement 2015}, doi = {10.1364/PV.2015.JTu5A.9}, pages = {JTu5A.9}, year = {2015}, language = {en} }