We have studied light randomization and the absorption enhancement in textured ultra-thin Al x Ga 1~x As films, with a thickness corresponding to a few optical wavelengths. A correlation between the degree of light randomization and trapping, with the scale length of the texturization geometry was found. The observed absorption enhancement corresponds to 90% of the best possible theoretical val...

We investigate the influence of refractive index contrast on the light scattering properties of nanotextured interfaces, which serve as front contact for p-i-n thin-film silicon solar cells. We here focus on ZnO surfaces with randomly oriented pyramidal features, known for their excellent light trapping performance. Transparent replicas, with a different refractive index, but practically identi...

1. Abstract The limitation associated with the low optical absorption remains to be the main technical barrier that constrains the efficiency of thin-film solar cells in energy conversion. Effective design of light-trapping structure is thus critical to increase light absorption in thin-film cells. However, light trapping in thin-film solar cell is a highly complex physical phenomenon governed ...

The ability to engineer a thin two-dimensional surface for light trapping across an ultra-broad spectral range is central for an increasing number of applications including energy, optoelectronics, and spectroscopy. Although broadband light trapping has been obtained in tall structures of carbon nanotubes with millimeter-tall dimensions, obtaining such broadband light-trapping behavior from nan...

We demonstrate numerically that photonic crystal dye-sensitized solar cells (DSSCs) can provide at least a factor of one-third enhancement in solar light absorption and power conversion efficiency relative to their conventional counterparts. Our design consists of a lattice of modulated-diameter TiO2 nanotubes filled with TiO2 nanoparticles and interstitial regions filled with electrolyte. This...

iv Abstract Optical trapping, discovered in the 70's, allows moving and stabilizing small objects which sizes varies from atoms to particles of several microns. This technique, based on momentum conservation, is particularly well suited for manipulating biological matter (cells, organelles, vesicles, functionalized particles , etc.) and offers interesting potentialities for research in biotechn...

We illustrate the possibility of light trapping and funneling in periodic arrays of metallic nanoparticles. A controllable minimum in the transmission spectra of such constructs arises from a collective plasmon resonance phenomenon, where an incident plane wave sharply localizes in the vertical direction, remaining delocalized in the direction parallel to the crystal plane. Using hybrid arrays ...