TY - JOUR A1 - Ringleb, F. A1 - Eylers, K. A1 - Teubner, T. A1 - Boeck, T. A1 - Symietz, Christian A1 - Bonse, Jörn A1 - Andree, Stefan A1 - Krüger, Jörg A1 - Heidmann, B. A1 - Schmid, M. A1 - Lux-Steiner, M. T1 - Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing N2 - A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD. KW - Femtosecond laser KW - Physical vapor deposition KW - Indium KW - Molybdenum substrate KW - Microconcentrator solar cell PY - 2016 DO - https://doi.org/10.1063/1.4943794 SN - 0003-6951 VL - 108 IS - 11 SP - 111904-1 EP - 111904-4 AN - OPUS4-35602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ernst, O. C. A1 - Böttcher, K. A1 - Fischer, Daniel A1 - Uebel, D. A1 - Teubner, T. A1 - Boeck, T. T1 - Morphogenesis of liquid indium microdroplets on solid molybdenum surfaces during solidification at normal pressure and under vacuum conditions N2 - Electrical and optical applications based on micro- and nanoparticles have specific demands on their interfacial properties. These properties are strongly related to atmospheric conditions to which the particles were exposed during their formation. In this study, metallic In microparticles are synthesized by solidification of In droplets on an amorphous Mo substrate at normal pressure and under vacuum conditions. The influence of ambient pressure on the interface and surface shape is investigated. While solidification at atmospheric pressure leads to collapsed particles with undisturbed contact to the substrate, low pressures result in smooth spherical particles but with cavities inside. Numerical simulations with COMSOL Multiphysics reveal different temperature profiles and heat flux in particles during solidification for both cases. This indicates different starting conditions of the solidification, which leads to the described phenomenon eventually. The investigation of the varying process conditions on the particle shape in combination with the calculated and measured temperature curves over time gives valuable insights into new approaches to synthesize micro- and nanoparticles with defined interfacial properties. Both ambient pressure and cooling rate provide well-controllable and reliable parameters for the realization of different interfacial shapes. KW - Morphogenesis KW - Indium KW - Microdroplet KW - Molybdenum PY - 2022 DO - https://doi.org/10.1021/acs.langmuir.1c02744 SN - 0743-7463 SN - 1520-5827 VL - 38 IS - 2 SP - 762 EP - 768 PB - ACS Publ. CY - Washington, DC AN - OPUS4-54242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Eylers, K. A1 - Teubner, T. A1 - Schramm, H.-P. A1 - Symietz, Christian A1 - Bonse, Jörn A1 - Andree, Stefan A1 - Heidmann, B. A1 - Schmid, M. A1 - Krüger, Jörg A1 - Boeck, T. T1 - Growth and shape of indium islands on molybdenum at micro-roughened spots created by femtosecond laser pulses N2 - Indium islands on molybdenum coated glass can be grown in ordered arrays by surface structuring using a femtosecond laser. The effect of varying the molybdenum coated glass substrate temperature and the indium deposition rate on island areal density, volume and geometry is investigated and evaluated in a physical vapor deposition (PVD) process. The joined impact of growth conditions and spacing of the femtosecond laser structured spots on the arrangement and morphology of indium islands is demonstrated. The results yield a deeper understanding of the island growth and its precise adjustment to industrial requirements, which is indispensable for a technological application of such structures at a high throughput, for instance as precursors for the preparation of Cu(In,Ga)Se2 micro concentrator solar cells. KW - Indium islands KW - Femtosecond laser patterning KW - Diffusion KW - CIGSe micro solar cells PY - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0169433216325764 DO - https://doi.org/10.1016/j.apsusc.2016.11.135 SN - 0169-4332 SN - 1873-5584 VL - 418 SP - 548 EP - 553 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-40551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Som, T. A1 - Simo, A. A1 - Fenger, R. A1 - Troppenz, G.V. A1 - Bansen, R. A1 - Pfänder, N. A1 - Emmerling, Franziska A1 - Rappich, J. A1 - Boeck, T. A1 - Rademann, K. T1 - Bismuth hexagons: facile mass synthesis, stability and applications N2 - A unique direct electrodeposition technique involving very high current densities, high voltages and high electrolyte concentrations is applied for highly selective mass synthesis of stable, isolable, surfactant-free, single-crystalline Bi hexagons on a Cu wire at room temperature. A formation mechanism of the hexagons is proposed. The morphology, phase purity, and crystallinity of the material are well characterized by FESEM, AFM, TEM, SAED, EDX, XRD, and Raman spectroscopy. The thermal stability of the material under intense electron beam and intense laser light irradiation is studied. The chemical stability of elemental Bi in nitric acid shows different dissolution rates for different morphologies. This effect enables a second way for the selective fabrication of Bi hexagons. Bi hexagons can be oxidized exclusively to α-Bi2O3 hexagons. The Bi hexagons are found to be promising for thermoelectric applications. They are also catalytically active, inducing the reduction of 4-nitrophenol to 4-aminophenol. This electrodeposition methodology has also been demonstrated to be applicable for synthesis of bismuth-based bimetallic hybrid composites for advanced applications. KW - Bismuth KW - Hexagons KW - Dendrites KW - Single-crystal KW - Thermoelectric applications KW - Catalytic applications PY - 2012 DO - https://doi.org/10.1002/cphc.201101009 SN - 1439-4235 VL - 13 IS - 8 SP - 2162 EP - 2169 PB - Wiley-VCH CY - Weinheim AN - OPUS4-26278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmid, M. A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Ernst, O. A1 - Andree, Stefan A1 - Bonse, Jörn A1 - Boeck, T. A1 - Krüger, Jörg T1 - Locally grown Cu(In,Ga)Se2 micro islands for concentrator solar cells N2 - Light concentration opens up the path to enhanced material efficiency of solar cells via increased conversion efficiency and decreased material requirement. For true material saving, a fabrication method allowing local growth of high quality absorber material is essential. We present two scalable fs-laser based approaches for bottom-up growth of Cu(In,Ga)Se2 micro islands utilizing either site-controlled assembly of In(,Ga) droplets on laser-patterned substrates during physical vapor deposition, or laser-induced forward transfer of (Cu,In,Ga) layers for local precursor arrangement. The Cu(In,Ga)Se2 absorbers formed after selenization can deliver working solar devices showing efficiency enhancement under light concentration. T2 - SPIE OPTO, 2018 CY - San Francisco, USA DA - 29.01.2018 KW - Chalcopyrite KW - Cu(In,Ga)Se2 KW - Fs-laser patterning KW - Laser-induced forward transfer KW - Micro solar cell PY - 2018 SN - 978-1-5106-1540-3 SN - 0277-786X SN - 1996-756X VL - 10527 SP - 1052707-1 EP - 1052707-9 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-44450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andree, Stefan A1 - Heidmann, B. A1 - Ringleb, F. A1 - Eylers, K. A1 - Bonse, Jörn A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Production of precursors for micro-concentrator solar cells by femtosecond laser-induced forward transfer N2 - Single-pulse femtosecond laser-induced forward transfer (LIFT, 30 fs, 790 nm) is used to deposit micron-sized dots of copper and/or indium onto a molybdenum layer on glass. Such systems can serve as precursors for the bottom-up manufacturing of micro-concentrator solar cells based on copper-indium-gallium-diselenide. The influence of the thickness of the copper, indium and combined copper-indium donor layers on the quality of the transferred dots was qualified by scanning electron microscopy, energy-dispersive X-ray analysis, and optical microscopy. The potential for manufacturing of a spatial arrangement adapted to the geometry of micro-lens arrays needed for micro-concentrator solar cells is demonstrated. T2 - EMRS Spring Meeting 2017, Symposium X “New frontiers in laser interaction: from hard coatings to smart materials" CY - Strasbourg, France DA - 22.05.2017 KW - Laser-induced forward transfer (LIFT) KW - Femtosecond laser KW - Micro-concentrator solar cell KW - Copper-indium-gallium-diselenide KW - CIGSe PY - 2017 DO - https://doi.org/10.1007/s00339-017-1282-x SN - 1432-0630 SN - 0947-8396 VL - 123 SP - Article 670, 1 EP - 8 AN - OPUS4-42273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Andree, Stefan A1 - Heidmann, B. A1 - Bonse, Jörn A1 - Eylers, K. A1 - Ernst, O. A1 - Boeck, T. A1 - Schmid, M. A1 - Krüger, Jörg T1 - Femtosecond laser-assisted fabrication of chalcopyrite micro-concentrator photovoltaics N2 - Micro-concentrator solar cells offer an attractive way to further enhance the efficiency of planar-cell technologies while saving absorber material. Here, two laser-based bottom-up processes for the fabrication of regular arrays of CuInSe2 and Cu(In,Ga)Se2 microabsorber islands are presented, namely one approach based on nucleation and one based on laser-induced forward transfer. Additionally, a procedure for processing these microabsorbers to functioning micro solar cells connected in parallel is demonstrated. The resulting cells show up to 2.9% efficiency and a significant efficiency enhancement under concentrated Illumination. KW - Chalcopyrite KW - Femtosecond laser patterning KW - Laser-induced forward transfer KW - Micro-concentrator solar cell KW - Photovoltaics PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-470026 DO - https://doi.org/10.3762/bjnano.9.281 SN - 2190-4286 VL - 9 SP - 3025 EP - 3038 PB - Beilstein-Institut zur Förderung der Chemischen Wissenschaften CY - Frankfurt, M. AN - OPUS4-47002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -