A5101402450- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Chalcogenide Semiconductor Thin Films
- Quantum Dots Synthesis And Properties
- Magnetic confinement fusion research
- Copper-based nanomaterials and applications
- Superconducting Materials and Applications
- Semiconductor materials and interfaces
- Plasmonic and Surface Plasmon Research
- Thin-Film Transistor Technologies
- solar cell performance optimization
- Gold and Silver Nanoparticles Synthesis and Applications
- Near-Field Optical Microscopy
- Particle Accelerators and Free-Electron Lasers
- Fusion materials and technologies
- Silicon and Solar Cell Technologies
- Perovskite Materials and Applications
- Phase-change materials and chalcogenides
- Photonic Crystals and Applications
- Microwave Engineering and Waveguides
- Plasma Diagnostics and Applications
- Retinal Imaging and Analysis
- Quantum, superfluid, helium dynamics
- Nonlinear Optical Materials Studies
- Ga2O3 and related materials
University of Duisburg-Essen
2017-2024
Karlsruhe Institute of Technology
2003-2020
Centro Científico Tecnológico - Nordeste
2020
Helmholtz-Zentrum Berlin für Materialien und Energie
2009-2019
Institut für Medizinische Biometrie, Informatik und Epidemiologie
2019
University of Bonn
2019
Thales (France)
2017-2019
Freie Universität Berlin
2008-2017
University of Lucerne
2017
California Institute of Technology
2013
We experimentally demonstrate photocurrent enhancement in ultrathin Cu(In,Ga)Se2 (CIGSe) solar cells with absorber layers of 460 nm by nanoscale dielectric light scattering patterns printed substrate conformal imprint lithography. show that patterning the front side device TiO2 nanoparticle arrays results a small almost entire 400-1200 spectral range due to enhanced coupling into cell. Three-dimensional finite-difference time-domain simulations are good agreement external quantum efficiency...
The development of high-power gyrotrons (118 GHz, 140 GHz) in continuous-wave (CW) operation for heating nuclear fusion plasmas has been progress several years a joint collaboration between different European research institutes and industrial partners. 140-GHz gyrotron being under the installation at W7-X stellarator now construction IPP Greifswald, Germany, operates TE/sub 28,8/ mode is equipped with diode type magnetron injection electron gun, an improved beam tunnel, high mode-purity...
Plasmonic scattering from metal nanostructures presents a promising concept for improving the conversion efficiency of solar cells. The determination optimal and their position within cell is crucial to boost efficiency. Therefore we established one-dimensional optical model combining plasmonic thin-film optics simulate properties cells including nanoparticles. Scattering models based on dipole oscillations Mie theory are presented integration in semi-coherent descriptions explained. A layer...
We theoretically compare the scattering and near field of nanoparticles from different types materials, each characterized by specific optical properties that determine interaction with light: metals their free charge carriers giving rise to plasmon resonances, dielectrics showing zero absorption in wide wavelength ranges, semiconductors combining two beforehand mentioned plus a band gap. Our simulations are based on Mie theory full 3D calculations Maxwell's equations finite element method....
Light management has gained wide interest for various types of solar cells. This paper reviews the application nanostructures light to chalcopyrite (CIGSe) type Firstly, relevance CIGSe cells will be introduced and concepts absorption enhancement discussed. The development ultra-thin examples nanoparticle fabrication techniques together with their chances challenges presented. Particular attention paid that have been applied cells, revealing many theoretical some experimental results....
Abstract Ultra‐thin Cu(In,Ga)Se 2 (CIGSe) solar cells on transparent conductive oxide back contact reduce the material consumption of rare indium and gallium simultaneously exhibit great potential for semi‐transparent bifacial application. For highly efficient CIGSe cells, a steep Ga grading Na treatment are expected. However, will promote formation resistive GaO x at rear interface owing to accumulation. In this work, three‐stage co‐evaporation process is renewed effect deposition sequence...
Photovoltaics—a mature technology—is set to play a vital role in achieving carbon-free energy system. This article examines the pivotal of optics advancing photovoltaics. We identify key scientific research areas where community can make significant contributions. are guided by central question: How facilitate large-scale deployment photovoltaics necessary for decarbonizing our societies?
Photovoltaics—a mature technology—is set to play a vital role in achieving carbon-free energy system. This article examines the pivotal of optics advancing photovoltaics. We identify key scientific research areas where community can make significant contributions. are guided by central question: How facilitate large-scale deployment photovoltaics necessary for decarbonizing our societies?
Photovoltaics—a mature technology—is set to play a vital role in achieving carbon-free energy system. This article examines the pivotal of optics advancing photovoltaics. We identify key scientific research areas where community can make significant contributions. are guided by central question: How facilitate large-scale deployment photovoltaics necessary for decarbonizing our societies?
22.2% relative enhancement of photocurrent in ultra-thin perovskite solar cells by one step incorporation plasmonic silver nanoparticles.
CuIn 1– x Ga Se 2 (CIGSe) solar cells have achieved record efficiency values as high 22.6% for small areas, with module of 16.5%. However, economic viability these must be reduced material consumption (especially indium), which requires reducing the CIGSe absorber thickness from 2000–3000 nm to below 500 nm. Soft‐imprinted SiO nanoparticles (NPs) beneath a conformal layer enable this reduction. Optically, they enhance absorption light through Fabry–Pérot and waveguided resonances within...
Ultrathin Cu(In,Ga)Se2 (CIGSe) solar cells pose challenges of incomplete absorption and back contact recombination. In this work, we applied the simple collodial nanosphere lithography fabricated 2D SiO2 nanomeshes (NMs), which simultaneously benefit ultrathin CIGSe electrically optically. Electrically, NMs are capable passivating recombination increasing minimum bandgap absorbers. Optically, parasitic in Mo as a main optical loss is reduced. Consequently, give rise to an increase 3.5 mA/cm2...
To investigate the effect of surface roughness on calculation optical constants, e.g., complex refractive index n+ik or (n,k) CuIn1−xGaxSe2 (CIGSe) thin films, we took CuInSe2 (CISe) and CuGaSe2 (CGSe) as examples applied “Modified Transfer-Matrix (MTM)” method to calculate constants with considering scattering due roughness. Compared (TM) without roughness, it was revealed that MTM could improve accuracy calculation. The calculated values from increase by 6.89% for CISe 2.59% CGSe in...
Karlsruhe Institute of Technology (KIT) is doing research and development in the field megawatt-class radio frequency (RF) sources (gyrotrons) for Electron Cyclotron Resonance Heating (ECRH) systems International Thermonuclear Experimental Reactor (ITER) DEMOnstration Fusion Power Plant that will follow ITER. In focus verification European coaxial-cavity gyrotron technology which shall lead to gyrotrons operating at an RF output power significantly larger than 1 MW CW above 200 GHz. A major...
Abstract The classification of photovoltaic technologies into generations aims at facilitating the overview and equally can support identification future trends. initial definition by Martin Green follows historical development, which however does not necessarily need to imply that a certain technology is old or outdated. To find an update early graph without immediately refusing classification, first, representation filled with up‐to‐date numbers. Despite several new definitions being...
In the first part of this paper, status 140-GHz continuously operated gyrotrons with an output power 1 MW for stellarator Wendelstein 7-X will be described. With series tube, 1000 kW has been achieved in short pulse operation (milliseconds) electron beam current 40 A, and 1150 at 50 A. a length 3 min limited by available high-voltage (HV) supply, 920 about A efficiency 45% mode purity 97.5% obtained. At reduced 29 570 was measured 1893 s without significant increase tube pressure. The energy...
Two antennae have been installed in JET and operated to the maximum design capability of generators. 4.5 MW, 10 MJ coupled plasma which heated up a stored energy 3 with central temperatures Te0=5 keV Ti0=4 without increase relative impurity concentration. Degradation confinement is observed according an L mode scaling. The effect k/sub //// shaping discussed using quadrupole antenna. Hydrogen helium minority heating regimes give similar results.
This work elaborates on the high scattering which dielectric nanorods exhibit and how it can be exploited to control light propagation across material interfaces. A detailed overview of interact with through a combination dipolar leaky modes is performed via outward power flux calculations. We establish account for design parameters that best result in magnification owing resonant behavior nanorods. Impact their dispersion have been calculated low loss oxides like ZnO when nanostructured...
To realize the high efficiency potential of perovskite/chalcopyrite tandem solar cells in modules, hydrogenated In2O3 (IO:H) as electrode is investigated. IO:H with an electron mobility 100 cm2 V−1 s−1 demonstrated. Compared to conventional Sn doped (ITO), exhibits a decreased concentration and leads almost no sub-bandgap absorption up wavelength 1200 nm. Without trade-off between transparency lateral resistance electrode, cell keeps increasing thickness increases efficiencies above 22% are...