nanostructure

Laser writing of nanostructured silicon arrays for the SERS detection of biomolecules with inhibited oxidation

The present work reports the processing of laser irradiated Si arrays (LISi) and underlines their surface enhanced Raman scattering (SERS) functionality. A nanostructured Si/SiOx surface forms providing additional fluidic and photoprotective …

Nanostructural changes upon substitutional Al doping in ZnO sputtered films

Al:ZnO layers, with low and high Al content, 0.2% and 2.1% cat. respectively, have been prepared using the RF magnetron sputtering technique. Noticeable differences in the optical and electrical properties have been detected in these films. With …

Lattice-Mismatch Induced Stress in Porous Silicon Films

We have studied the stress in porous silicon films with different porosities at the interface with the substrate. Micro-Raman spectra were measured along a cleaved cross section to sample different layer depths. Each spectrum was fit to the phonon …

Determination of Stress in Porous Silicon by Micro-Raman Spectroscopy

We have studied the stress in porous silicon films as a function of depth and porosity using micro-Raman spectroscopy. Raman spectra were measured at different points along a cross section cleaved normal to the layer planes. Each spectrum was fitted …

Depth-Resolved Microspectroscopy of Porous Silicon Multilayers

We have measured depth-resolved microphotoluminescence (PL) and micro-Raman spectra on the cross section of porous silicon multilayers to sample different layer depths. The PL emission band gets stronger, blueshifts, and narrows at the high porosity …

Electrooptics: Phenomena, materials and applications

This comprehensive text provides an understanding of the physical phenomenon behind electrooptics. It describes in detail modern electrooptic materials and operative physical mechanisms, and devotes a full chapter to the new materials engineering …

Electronic energy levels of quantum well wires

An efficient variational method to solve the two‐dimensional Schrödinger equation using a basis set of cubic $B$ splines is introduced. The method, which uses the effective mass theory and the envelope function approximation, is applied to find the …

Local origin of photocurrent in semiconductor superlattices

To trace the origin of photocurrent (PC) in semiconductor superlatices, we have studied the PC spectra as a function of the applied electric field in a novel compositionally graded superlattice, where each well produces a separate peak. The sample …

Change in dimensionality of superlattice excitons induced by an electric field

We have observed an electric-field-induced change in the dimensionality of excitons in superlattices, from three to quasi-two dimensions. The exciton binding energy of a (40 Å/(40 Å) GaAs/(GaAl)As superlattice, determined from low-temperature …

Coherence and localization in semiconductor superlattices under electric fields

Using optical techniques, we have demonstrated that the quantum coherence of electron states in GaAs/GaAlAs superlattices under electric fields increases drastically as the period, $D$, and the electric field, $\cal{E}$, decrease, reaching at least …