Silicon nanowires can enhance broadband optical absorption and reduce radial carrier collection distances in solar cell devices. Arrays of disordered nanowires grown by vapor-liquid-solid method are attractive because they can be grown on low-cost substrates such as glass, and are large area compatible. Here, we experimentally demonstrate that an array of disordered silicon nanowires surrounded...

Let G be a planar graph with n vertices whose vertex set is partitioned into subsets V0, . . . , Vk−1 for some positive integer 1 ≤ k ≤ n and let S be a set of n distinct points in the plane partitioned into subsets S0, . . . , Sk−1 with |Vi| = |Si| (0 ≤ i ≤ k − 1). This paper studies the problem of computing a crossing-free drawing of G such that each vertex of Vi is mapped to a distinct point...

The mechanism of DC-Electric-Field-Induced Second-Harmonic (EFISH) generation at weakly nonlinear buried Si(001)-SiO2 interfaces is studied experimentally in planar Si(001)-SiO2-Cr MOS structures by optical secondharmonic generation (SHG) spectroscopy with a tunable Ti:sapphire femtosecond laser. The spectral dependence of the EFISH contribution near the direct two-photon E1 transition of silic...

Recently, ultrathin crystalline silicon solar cells have gained tremendous interest because they are deemed to dramatically reduce material usage. However, the resulting conversion efficiency is still limited by the incomplete light absorption in such ultrathin devices. In this letter, we propose ultrathin a-Si/c-Si tandem solar cells with an efficient light trapping design, where a nanopyramid...

Hexagonal barium ferrite thick films (50–200μm) have been deposited on Si and Al2O3/Si substrates using a screen printing technique. X-ray diffractometry, scanning electron microscopy and magnetometry were used to characterize and correlate the ferrite films’ microstructure and magnetic properties. The experiments indicated that an Al2O3 underlayer was effective in preventing silicon diffusion ...

New memory structures using threshold shifting from charge stored in quantum dots (QDs) and quantum rings (QRs) of Germanium (Ge) are described. The QDs and QRs of Ge were prepared on a p-Si (100) matrix by means of pulsed laser deposition (PLD) using the droplet technique combined with rapid annealing. The perfect planar nanorings with welldefined sharp inner and outer edges were formed via an...

We report here several different superlattice photonic crystal based designs for 200nm thick c-Si solar cells, demonstrating that these structures have the ability to increase broadband absorption from λ = 300nm to 1100nm by more than 100% compared to a planar cell with an optimized anti-reflection coating. We show that adding superlattices into photonic crystals introduces new optical modes th...

By mechanical exfoliation, it is possible to deposit atomically thin mica flakes down to single-monolayer thickness on SiO2/Si wafers. The optical contrast of these mica flakes on top of a SiO2/Si substrate depends on their thickness, the illumination wavelength, and the SiO2 substrate thickness, and can be quantitatively accounted for by a Fresnel-law-based model. The preparation of atomically...