We report on the fabrication of disordered nanostructures by combining colloidal lithography and silicon etching. We show good control of the short-range ordered colloidal pattern for a wide range of bead sizes from 170 to 850 nm. The inter-particle spacing follows a Gaussian distribution with the average distance between two neighboring beads (center to center) being approximately twice their diameter, thus enabling the nanopatterning with dimensions relevant to the light wavelength scale.
View Article and Find Full Text PDFIn this paper, we present the integration of an absorbing photonic crystal within a monocrystalline silicon thin film photovoltaic stack fabricated without epitaxy. Finite difference time domain optical simulations are performed in order to design one- and two-dimensional photonic crystals to assist crystalline silicon solar cells. The simulations show that the 1D and 2D patterned solar cell stacks would have an increased integrated absorption in the crystalline silicon layer would increase of respectively 38% and 50%, when compared to a similar but unpatterned stack, in the whole wavelength range between 300 nm and 1100 nm.
View Article and Find Full Text PDFWe propose a novel system of dual-wavelength micro-cavity based on the coupling between a photonic crystal membrane (PCM); operating at the Γ- point of the Brillouin zone, with a Fabry-Perot vertical cavity (FP). The optical coupling, which can be adjusted by the overlap between both optical modes, leads to the generation of two hybrid modes separated by a frequency difference which can be tuned using micro-opto-electromechanical structures. The proposed dual-wavelength micro-cavity is attractive for application where dual-mode behaviour is desirable as dual-lasing, frequency conversion.
View Article and Find Full Text PDFWe report on the absorption of a 100nm thick hydrogenated amorphous silicon layer patterned as a planar photonic crystal (PPC), using laser holography and reactive ion etching. Compared to an unpatterned layer, electromagnetic simulation and optical measurements both show a 50% increase of the absorption over the 0.38-0.
View Article and Find Full Text PDFWe propose a design that increases significantly the absorption of a thin layer of absorbing material such as amorphous silicon. This is achieved by patterning a one-dimensional photonic crystal (1DPC) in this layer. Indeed, by coupling the incident light into slow Bloch modes of the 1DPC, we can control the photon lifetime and then, enhance the absorption integrated over the whole solar spectrum.
View Article and Find Full Text PDF2D photonic crystal (2D PC) structures consisting in a square lattice of Indium Phosphide (InP) microrods bonded on a Silicon/Silica Bragg mirror are experimentally investigated. We focus on slow Bloch modes above the light line, especially at the Gamma-point where a vertical emission can be obtained. Stimulated emission around 1.
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