Related papers: A Model for the Optical Absorption in Porous Silic…
In this paper, we report on the optical absorption in porous silicon. We model the absorption process assuming that porous silicon is a pseudo 1D material system having a distribution of band gaps. We show that in order to explain the…
The use of cryogenic silicon as a detector medium for dark matter searches is gaining popularity. Many of these searches are highly dependent on the value of the photoelectric absorption cross section of silicon at low temperatures,…
We report on simulations and measurements of the optical absorption of silicon nanowires (NWs) versus their diameter. We first address the simulation of the optical absorption based on two different theoretical methods : the first one,…
We develop a first-principles theory of phonon-assisted optical absorption in semiconductors and insulators which incorporates the temperature dependence of the electronic structure. We show that the Hall-Bardeen-Blatt theory of indirect…
The absorption spectra of silicon nanowires (SiNW) are calculated using semi-empirical $sp^{3}d^{5}s^{*}$ tight binding (TB) and Density Functional Theory (DFT) methods. The role of diameter, wave function symmetry, strain and…
The optical properties of silicon can be greatly tuned by applying strain and opening new perspectives, particularly in applications where infrared is key. In this work, we use a recent model for the indirect light absorption of silicon and…
Absorption imaging is a commonly adopted method to acquire, with high temporal resolution, spatial information on a partially transparent object. It relies on the interference between a probe beam and the coherent response of the object. In…
We introduce a real-space approach to understand the relationship between optical absorption and crystal structure. We apply this approach to alternative phases of silicon, with a focus on the Si$_{20}$ crystal phase as a case study. We…
Since thin-film silicon solar cells have limited optical absorption, we explore the effect of a nanostructured back reflector to recycle the unabsorbed light. As a back reflector we investigate a 3D photonic band gap crystal made from…
In this study, we investigate the optical absorption within the conduction-subbands of a cylindrical GaN/AlN quantum wire. We analyze the optical absorption rate and the real part of the dielectric function for both quantum wire (QWR) and…
A high quality amorphous silicon (a-Si) nanostructures has grown experimentally to study the origin of light emission and the quantum confinement effect in a-Si. The quantum confinement effect increases the band gap of material as the size…
We report on very high enhancement of thin layer's absorption through band-engineering of a photonic crystal structure. We realized amorphous silicon (aSi) photonic crystals, where slow light modes improve absorption efficiency. We show…
The phonon-assisted interband optical absorption spectrum of silicon is calculated at the quasiparticle level entirely from first principles. We make use of the Wannier interpolation formalism to determine the quasiparticle energies, as…
Future laser-interferometric gravitational wave detectors (GWDs) will potentially employ test mass mirrors from crystalline silicon and a laser wavelength of $1550\,\rm{nm}$, which corresponds to a photon energy below the silicon bandgap.…
We describe a method for calculating the probability with which the wall of a plasma absorbs an electron at low energy. The method, based on an invariant embedding principle, expresses the electron absorption probability as the probability…
The infrared range optical absorption mechanism of Carbon-Copper composite thin layer coated on the Diamond-Like Carbon (DLC) buffer layer has been investigated. By consideration of weak interactions between copper nanoparticles in their…
Crystalline silicon is currently being discussed as test-mass material for future generations of gravitational wave detectors that will operate at cryogenic temperatures. We present optical absorption measurements on a large-dimension…
The photosensitivity of silicon is inherently very low in the visible electromagnetic spectrum, and it drops rapidly beyond 800 nm in near-infrared wavelengths. Herein, we have experimentally demonstrated a technique utilizing…
The experimental results presented in this paper show the influence of the elastic deformation of porous solids on the adsorption process. With p+-type porous silicon formed on highly boron doped (100) Si single crystal, we can make…
Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal stuctures of silicon carbide (SiC) are presented from 1200--35,000 cm$^{-1}$ ($\lambda \sim$ 8--0.28 $\mu$m) and used to improve the…