Abstract: The present invention relates to an electrolyte for use in metal-air batteries comprising at least one polyalkylene glycol containing ethylene oxide or propylene oxide units or mixtures thereof in an alkaline solution. Further, the invention relates to a metal-air battery comprising an anode, a cathode and an ion-conducting electrolyte interposed therebetween, wherein the anode contains a metal selected from the group of aluminum (Al), iron (Fe), lithium (Li), zinc (Zn), magnesium (Mg) or silicon (Si) and the cathode is an air electrode and the electrolyte comprises at least one polyalkylene glycol containing ethylene oxide or propylene oxide units or mixtures thereof in an alkaline solution.

Abstract: A solar cell and a method for producing a solar cell are described, comprising at least one photovoltaic layer region (1) which at least partially absorbs photons (6) incident therein, whose photon energy is greater than a minimum photon energy Emin, and releases electrical charge carriers in the form of electron-hole pairs, which are spatially separable within the photovoltaic layer region (1) and can be tapped via at least two electrodes (2), which are electrically connected to the photovoltaic layer region (1), to implement an electrical voltage, and comprising at least one interaction layer (3 and/or 4), which at least partially overlaps the photovoltaic layer region, in which at least a part of the incident photons (6) are subject to an interaction with emission of photons of higher or lower photon energy than that of the incident photons.

Abstract: The present invention provides a method for fast switching of optical properties in photonic crystals using pulsed/modulated free-carrier injection. The results disclosed herein indicate that several types of photonic crystal devices can be designed in which free carriers are used to vary dispersion curves, stop gaps in materials with photonic bandgaps to vary the bandgaps, reflection, transmission, absorption, gain, or phase. The use of pulsed free carrier injection to control the properties of photonic crystals on fast timescales forms the basis for all-optical switching using photonic crystals. Ultrafast switching of the band edge of a two-dimensional silicon photonic crystal is demonstrated near a wavelength of 1.9 ?m. Changes in the refractive index are optically induced by injecting free carriers with 800 nm, 300 fs pulses. Band-edge shifts have been induced in silicon photonic crystals of up to 29 nm that occurs on the time-scale of the pump pulse.

Abstract: The present invention provides a method for fast switching of optical properties in photonic crystals using pulsed/modulated free-carrier injection. The results disclosed herein indicate that several types of photonic crystal devices can be designed in which free carriers are used to vary dispersion curves, stop gaps in materials with photonic bandgaps to vary the bandgaps, reflection, transmission, absorption, gain, or phase. The use of pulsed free carrier injection to control the properties of photonic crystals on fast timescales forms the basis for all-optical switching using photonic crystals. Ultrafast switching of the band edge of a two-dimensional silicon photonic crystal is demonstrated near a wavelength of 1.9 &mgr;m. Changes in the refractive index are optically induced by injecting free carriers with 800 nm, 300 fs pulses. Band-edge shifts have been induced in silicon photonic crystals of up to 29 nm that occurs on the time-scale of the pump pulse.