Related papers: Improved Light Absorption by Quantum Confinement a…
We have performed first-principles calculations of Si/SiO$_2$ superlattices in order to examine their electronic states, confinement and optical transitions, using linearized-augmented-plane-wave techniques and density-functional theory.…
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…
Epitaxially-grown quantum well and quantum dot solar cells suffer from weak light absorption, strongly limiting their performance. Light trapping based on optical resonances is particularly relevant for such devices to increase light…
We present a theoretical analysis of intraband optical transitions from the intermediate pseudo-band of confined states to the conduction band in a finite, inhomogeneous stack of self-assembled semiconductor quantum dots. The chain is…
We have calculated electronic and optical properties of Si/BeSe$_{0.41}$Te$_{0.59}$ heterostructures by a semiempirical $sp^{3}s^{*}$ tight-binding method. Tight-binding parameters and band bowing of BeSe$_{0.41}$Te$_{0.59}$ are considered…
Because of its low-cost, silicon is the standard material for photovoltaic conversion. Yet, its band-edge absorption spectrum is narrower than the spectrum of the solar radiation, which reduces its conversion efficiency. In this paper, it…
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…
Light trapping in sub-wavelength semiconductor nanowires (NWs) offers a promising approach to simultaneously reducing material consumption and enhancing photovoltaic performance. Nevertheless, the absorption efficiency of a NW, defined by…
We present a multiscale approach for modeling an intermediate-band solar cell based on a GaAs-GaAlAs quantum dot superlattice of cubic symmetry. Our framework combines high-accuracy theoretical calculations of the superlattice band…
Intermediate band solar cells (IBSCs) pursue the increase in efficiency by absorbing below-bandgap energy photons while preserving the output voltage. Experimental IBSCs based on quantum dots have already demonstrated that both…
Energy states below the bandgap of a semiconductor, such as trap states or charge transfer states in organic donor acceptor blends, can contribute to light absorption. Due to their low number density or ultrasmall absorption cross-section,…
The design and fabrication of a metal-dielectric-metal absorber that achieves strong absorption from the ultraviolet (UV) to the near-infrared (near-IR) spectrum are presented. The proposed nanostructure consists of a periodic titanium (Ti)…
Thin films are preferred for high photocurrent conversion efficiency, but strong photon absorption at photon energies below the bandgap (near and shortwave infrared) typically requires thicker semiconductor layers. To address this tradeoff,…
Numerical simulation of a solar cell can provide various information that can be useful to maximize its power conversion efficiency (PCE). In that respect we carried out a set of numerical simulation using AFORS-HET simulation program.…
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…
We propose a back-reflecting scheme in order to enhance the maximum achievable current in one micron thick crystalline silicon solar cells. We perform 3-dimensional numerical investigations of the scattering properties of metallic…
In$_2$Se$_3$ in the three-dimensional (3D) hexagonal crystal structure with space group $P6_1$ ($\gamma$-In$_2$Se$_3$) has a direct band gap of $\sim$1.8 eV and high absorption coefficient, making it a promising semiconductor material for…
We propose an efficient plasmonic structure consisting of metal strips and thin-film silicon for solar energy absorption. We numerically demonstrate the absorption enhancement in symmetrical structure based on the mode coupling between the…
Organic solar cells (OSCs) are uniquely suited for semitransparent applications due to their adjustable absorption spectrum. However, most high-performance semitransparent cells reported to date are based on materials that have shown high…
We optimized micro-holes in a thin slab for fast Si photodetectors at wavelength 800-950nm. Lateral modes are shown to be responsible for the effective light trapping. Small disorder and cone hole shapes helped achieve uniform quantum…