Beyond the Yablonovitch limit: Trapping light by frequency shift

Solar Cell light trapping beyond the ray optic limit.

In 1982, Yablonovitch proposed a thermodynamic limit on light trapping within homogeneous semiconductor slabs, which implied a minimum thickness needed to fully absorb the solar spectrum. However, this limit is valid for geometrical optics but not for a new generation of subwavelength solar absorbers such as ultrathin or inhomogeneously structured cells, wire-based cells, photonic crystal-based...

Spectral Shift Function for Trapping Energies in the Semiclassical Limit

Light Quarks beyond Chiral Limit

In this talk we discuss an improvement of the Diakonov-Petrov QCD Effective Action. We propose the Improved Effective Action, which is derived on the basis of the Lee-Bardeen results for the quark determinant in the instanton field. The Improved Effective Action provides proper account of the current quark masses, which is particularly important for strange quarks. This Action is successfully t...

Light trapping in solar cells at the extreme coupling limit

Ali Naqavi,* Franz-Josef Haug, Corsin Battaglia, Hans Peter Herzig, and Christophe Ballif Photovoltaics and Thin Film Electronics Laboratory, Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue A.-L. Breguet 2, Neuchâtel 2000, Switzerland Optics & Photonics Technology Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue A.-L. Breguet 2, Neuchâte...

Fundamental limit of light trapping in grating structures.

We use a rigorous electromagnetic approach to analyze the fundamental limit of light-trapping enhancement in grating structures. This limit can exceed the bulk limit of 4n², but has significant angular dependency. We explicitly show that 2D gratings provide more enhancement than 1D gratings. We also show the effects of the grating profile's symmetry on the absorption enhancement limit. Numerica...