0000000000115744
AUTHOR
Falk Lederer
showing 8 related works from this author
3D photonic crystal intermediate reflectors for enhanced light-trapping in tandem solar cells
2012
The concept of 3D photonic crystals embedded in tandem solar cells as intermediate reflective layers is investigated. Numerical as well as experimental results will be presented.
Optimization of soliton transmissions in dispersion-managed fiber links
1998
We propose a simple optimization criterion (including the best launch point position in-between amplifiers) for the design of soliton transmission lines. The present approach is shown to minimize energy scattering from the solitons into the continuum.
Impact of slow gain dynamics on soliton molecules in mode-locked fiber lasers
2012
International audience; We theoretically demonstrate and experimentally confirm the major influence of gain dynamics on soliton molecules that self-assemble in mode-locked lasers. Both slow gain recovery and depletion play a pivotal role in the formation of chirped soliton molecules characterized by an increasing separation from leading to trailing pulses. These chirped molecules actually consist of many pulses and may be termed macromolecules. They are experimentally observed in a fiber laser and numerically modeled by an approach that properly includes the slow gain dynamics. Furthermore, it is shown that these processes stabilize soliton trains in fiber lasers by inhibiting internal osci…
Three-dimensional photonic crystal intermediate reflectors for enhanced light-trapping in tandem solar cells
2011
A three-dimensional photonic crystal intermediate reflector for enhanced light trapping in tandem solar cells is presented. The intermediate reflector consists of a transparent and conductive ZnO:Al inverted opal sandwiched in between the top amorphous silicon and bottom microcrystalline silicon cell.
Photonic crystal intermediate reflector in micromorph tandem solar cells
2011
Experimental and numerical evidences are presented which show that the efficiency of silicon based tandem solar-cells can be increased by incorporating a three-dimensional photonic crystal as an intermediate reflector.
3D photonic crystal intermediate reflector for micromorph thin-film tandem solar cell
2008
The concept of 3D photonic intermediate reflectors for micromorph silicon tandem solar cells has been investigated. In thin-film silicon tandem solar cells consisting of amorphous and microcrystalline silicon with two junctions of a-Si/μc-Si, efficiency enhancements can be achieved by increasing the current density in the a-Si top cell. It is one goal to provide an optimized current matching at high current densities. For an ideal photon-management between top and bottom cell, a spectrally selective intermediate reflective layer (IRL) is necessary, which is less dependent of the angle of incidence than state-of-the-art thickness dependent massive interlayers. The design, preparation and cha…
Effect of slow gain dynamics in mode-locked fiber lasers: Chirped soliton molecules
2012
We theoretically and experimentally demonstrate the pivotal role of the gain dynamics in the formation of chirped soliton molecules in mode-locked lasers. Such molecules are characterized by an increasing separation from leading to trailing pulses.
Micromorph silicon tandem solar cells with fully integrated 3D photonic crystal intermediate reflectors
2010
A 3D photonic intermediate reflector for textured micromorph silicon tandem solar cells has been investigated. In thin-film silicon tandem solar cells consisting of amorphous and microcrystalline silicon with two junctions of a-Si/c-Si, efficiency enhancements can be achieved by increasing the current density in the a-Si top cell providing an optimized current matching at high current densities. For an ideal photon-management between top and bottom cell, a spectrally-selective intermediate reflective layer (IRL) is necessary. We present the first fully-integrated 3D photonic thin-film IRL device incorporated on a planar substrate. Using a ZnO inverted opal structure the external quantum eff…