Spectrally-resolved measurement of concentrated light distributions for Fresnel lens concentrators.

A test method that measures spectrally resolved irradiance distribution for a concentrator photovoltaic (CPV) optical system is presented. In conjunction with electrical I-V curves, it is a means to visualize and characterize the effects of chromatic aberration and nonuniform flux profiles under controllable testing conditions. The indoor characterization test bench, METHOD (Measurement of Electrical, Thermal and Optical Devices), decouples the temperatures of the primary optical element (POE) and the cell allowing their respective effects on optical and electrical performance to be analysed.

Plasmon-enhanced nonlinear optical properties of SiC nanoparticles.

An original plasmonic nano-Ag/SiN(x) substrate was elaborated to strongly enhance the nonlinear response of SiC NPs for the first time. A plasmon-induced two order of magnitude increase of second-harmonic generation and two-photon excited photoluminescence was experimentally achieved. The measured enhancement factors were correlated with local field intensities theoretically estimated by finite-difference time-domain calculations.

Nanostructured silicon nitride thin films for label-free multicolor luminescent cell imaging.

The application of nanostructured luminescent silicon nitride (SiN(X)) thin films for label-free cell imaging is reported for the first time. Different strong local fields ensured by various molecules concentrated in various cell compartments can lead to the creation of preferential electronic conditions for radiative recombination of photogenerated charge carriers via a given electronic channel. Thus, highly contrasted multicolor luminescent cell imaging under one photon excitation becomes possible.

Strong photoluminescence enhancement of silicon quantum dots by their near-resonant coupling with multi-polar plasmonic hot spots.

Localization of quantum dots (QDs) in the vicinity of metal nanoparticles (NPs) is known as one of the most efficient ways to increase their photoluminescence (PL). Despite the important recent advances achieved in II-VI QDs, only a seven-fold plasmon-induced PL enhancement is reported for Si QDs. In our paper we show that the plasmon-induced strong local PL enhancement of Si QDs in an SiN matrix can reach a 60-fold gain level.

Absorbing one-dimensional planar photonic crystal for amorphous silicon solar cell.

We 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.