Related papers: Indirect light absorption model for highly straine…
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,…
Silicon's inherently indirect bandgap severely limits its radiative efficiency, posing a fundamental challenge to the development of practical silicon-based light sources. While strategies such as nanoscale confinement of electrons and…
The unique terahertz properties of graphene has been identified for novel optoelectronic applications. In a graphene sample with bias voltage added, there is an enhanced absorption in the far infrared region and a diminished absorption in…
The nonlinear response of materials, an increasingly important aspect of light-matter interaction, can be challenging to measure in highly absorbing materials. Here, we introduce an interferometric technique that enables a direct…
Silicon carbide (SiC) is an indirect-gap semiconductor material widely used in electronic and optoelectronic applications. While experimental measurements of the phonon-assisted absorption coefficient of SiC across its indirect gap have…
InSe, a member of the layered materials family, is a superior electronic and optical material which retains a direct bandgap feature from the bulk to atomically thin few-layers and high electronic mobility down to a single layer limit. We,…
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…
In this paper, we analyse the optical absorption in porous silicon . This is the first attempt to explicitly demonstrate that it is not possible to extract the band gap of such low dimensional nanostructures like porous silicon from a Tauc…
We theoretically show that energy absorption in crystalline silicon can be controlled by two-color femtosecond double-pulse irradiation, in which two temporally separated pulses with different wavelengths interact sequentially with the…
We experimentally demonstrate that the addition of partial lattice disorder to a thin-film micro-crystalline silicon photonic crystal results in the controlled spectral broadening of its absorption peaks to form quasi resonances; increasing…
We employ the first-principles GW+Bethe Salpeter equation approach to study the electronic structure and optical absorption spectra of uniaxial strained graphene with many-electron effects included. Applied strain not only induces an…
We investigate the temperature effect on the electronic band structure and optical absorption property of wide-band-gap ternary nitride MgSiN$_2$ using first-principles calculations. We find that electron-phonon coupling leads to a sizable…
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,…
The ultrathin nature and dangling bonds free surface of two-dimensional (2D) semiconductors allow for significant modifications of their band gap through strain engineering. Here, thin InSe photodetector devices are biaxially stretched,…
We study optical properties of two dimensional silicene using density functional theory based calculations. Our results on optical response property calculations show that they strongly depend on direction of polarization of light, hence…
We calculate the maximal absorption enhancement obtainable by guided mode excitation in a weakly absorbing dielectric slab over wide wavelength ranges. The slab mimics thin film silicon solar cells in the low absorption regime. We consider…
Pieces of $n$-type silicon with 3.5 k$\Omega \cdot $cm resistivity have been irradiated by reactor neutrons to fluences of (1, 5 and 10) $\times 10^{16}$ cm$^{-2}$. Using light-transmission measurements, the absorption coefficients have…
A detailed theoretical study of the optical absorption in self-assembled quantum dots is presented in this paper. A rigorous atomistic strain model as well as a sophisticated electronic band structure model are used to ensure accurate…
We show that a weakly absorbing, strongly scattering (white) medium can be made very strongly absorbing at any frequency within its strong-scattering bandwidth by optimizing the input electromagnetic field. For uniform absorption, results…
Hexagonal boron nitride is an indirect band gap material with a strong luminescence in the ultraviolet. This luminescence originates from bound excitons recombination assisted by different phonon modes. The coupling between excitons and…