Gabler F.,Fraunhofer Institute for Electronic Nano Systems |
Roscher F.,Fraunhofer Institute for Electronic Nano Systems |
Doring R.,Fraunhofer Institute for Electronic Nano Systems |
Otto A.,Fraunhofer Institute for Electronic Nano Systems |
And 9 more authors.
China Semiconductor Technology International Conference 2016, CSTIC 2016 | Year: 2016
This paper gives an overview of technologies and materials for microsystems and electronics in harsh environmental applications including the fabrication of a multifunctional MEMS with platinum metallization, high-temperature stable CMOS circuits and trench capacitors, ceramic-based packaging technologies as well as analysis of material parameters, simulation and reliability testing. © 2016 IEEE.
Pascual M.J.,CSIC - Institute of Ceramics and Glass |
Garrido C.,CSIC - Institute of Ceramics and Glass |
Duran A.,CSIC - Institute of Ceramics and Glass |
Miguel A.,Polytechnic University of Valencia |
And 6 more authors.
International Journal of Applied Glass Science | Year: 2016
Transparent glass-ceramics containing Er3+-doped sodium lutetium fluoride nanocrystals for photonic applications have been synthesized. Glass transition temperature, softening temperature, and crystallization temperature were estimated by dilatometry and differential thermal analysis. Proper heat treatments were selected to crystallize lutetium fluoride nanocrystals. X-ray diffraction analysis was carried out to identify the crystalline phase and the crystal size. HRTEM indicates that the base glass is phase separated in droplets enriched in Lu, Na, F, and also Er ions. The thermal treatment induces the crystallization inside the droplets. The optical characterization, which includes absorption and steady-state and time-resolved emission spectroscopy under one- and two-photon excitation, shows the differences between the phase-separated base glass and its corresponding glass-ceramic. The reduction of the Judd-Ofelt parameter Ω2 together with the increase of the fluorescence lifetimes as compared to the glass sample confirms the presence of Er3+ ions in a crystalline environment in the glass-ceramic samples. Moreover, an enhancement of the green and red up-converted emissions (as well as the weak blue emission) is observed in the glass-ceramic, indicating the Er3+ incorporation into the nanocrystals. The possible excitation mechanisms responsible for this up-conversion luminescence are discussed on the basis of lifetime measurement results. © 2015 The American Ceramic Society and Wiley Periodicals, Inc.
Schumann M.F.,Karlsruhe Institute of Technology |
Wiesendanger S.,Friedrich - Schiller University of Jena |
Goldschmidt J.C.,Fraunhofer Institute for Solar Energy Systems |
Blasi B.,Fraunhofer Institute for Solar Energy Systems |
And 7 more authors.
Optica | Year: 2015
Nontransparent contact fingers on the sun-facing side of solar cells represent optically dead regions which reduce the energy conversion per area. We consider two approaches for guiding the incident light around the contacts onto the active area. The first approach uses graded-index metamaterials designed by two-dimensional Schwarz–Christoffel conformal maps, and the second uses freeform surfaces designed by one-dimensional coordinate transformations of a point to an interval. We provide proof-of-principle demonstrators using direct laser writing of polymer structures on silicon wafers with opaque contacts. Freeform surfaces are amenable to mass fabrication and allow for complete recovery of the shadowing effect for all relevant incidence angles. © 2015 Optical Society of America.
Naumann F.,Fraunhofer Institute for Microstructure of Materials and Systems IMWS |
Brand S.,Fraunhofer Institute for Microstructure of Materials and Systems IMWS
2016 17th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2016 | Year: 2016
The excitation and propagation of acoustic waves as employed in scanning acoustic microscopy follows highly complex phenomena which commonly cannot be visualized experimentally. The current paper describes the application of modelling and numerical simulation of these phenomena in structures like complex microelectronic samples or acoustic lenses. The design of acoustic lenses and their active elements have been optimized based on the numerical studies performed here. Simulation based visualization of the wave propagation and energy conversion in a Through Silicon Via with different defects at 1 GHz acoustic frequency supported the understanding and interpretation of the received acoustic signals. © 2016 IEEE.
Seidel S.,Friedrich - Schiller University of Jena |
Patzig C.,Fraunhofer Institute for Microstructure of Materials and Systems IMWS |
Hoche T.,Fraunhofer Institute for Microstructure of Materials and Systems IMWS |
Krause M.,Fraunhofer Institute for Microstructure of Materials and Systems IMWS |
And 7 more authors.
RSC Advances | Year: 2016
Glasses with the mol% composition of 51.9SiO2/21.2Al2O3/21.2MgO/5.7ZrO2 without and with the addition of 2.5 mol% Y2O3 were melted and subsequently transformed into glass-ceramics via annealing. Both glass-ceramics show strong differences in the microstructure and in the phase composition after crystallization at 950 °C for 5 h and subsequently at 1060 °C for different annealing times. In the glass without Y2O3, the main crystal phase is a quartz solid solution accompanied by the precipitation of ZrO2 and spinel. By contrast, glass-ceramics without the presence of a quartz solid solution were observed after the crystallization of the Y2O3-containing glass, using the same heat treatment. This is confirmed by analytical scanning transmission electron microscopy analysis and X-ray absorption near-edge structure spectroscopy data gathered at the Zr L2-, Y L2,3-, Si K- and Al L-edges. Furthermore, using X-ray absorption spectroscopy the coordination of the respective elements is analysed, and changes of the coordination during crystallization are monitored. © 2016 The Royal Society of Chemistry.