Search results for "Semiconductor"
showing 10 items of 974 documents
Theoretical Study of the Charge Transfer Exciton Binding Energy in Semiconductor Materials for Polymer:Fullerene-Based Bulk Heterojunction Solar Cells
2019
Recent efforts and progress in polymer solar cell research have boosted the photovoltaic efficiency of the technology. This efficiency depends not only on the device architecture but also on the material properties. Thus, insight into the design of novel semiconductor materials is vital for the advancement of the field. This paper looks from a theoretical viewpoint into two of the factors for the design of semiconductor materials with applications to bulk heterojunction solar cells: the charge transfer exciton binding energy and the nanoscale arrangement of donor and acceptor molecules in blend systems. Being aware that the exciton dissociation of local excitons in charge transfer states in…
Tumor mutational burden on cytological samples: A pilot study.
2020
Background Immune-checkpoint inhibitors (ICIs) represent an important treatment option for patients who have advanced stage non-small cell lung cancer (NSCLC). Currently, evaluation of the expression level of programmed death-ligand 1 (PD-L1) has proven highly successful as a positive predictive biomarker for ICIs. In addition to PD-L1, other promising predictive biomarkers are emerging, including high tumor mutational burden (TMB-H). However, measuring TMB-H remains challenging for several reasons, among which is the difficulty in obtaining adequate tissue material from NSCLC patients. There are no data in the current literature regarding the possibility of adopting cell blocks (CBs) for T…
Self — Assembled System: Semiconductor and Virus Like Particles
2008
Virus like nanoparticles (VLP) are in use to be absorbed by cells to cause biological effects. To increase a local concentration of VLP, nanoparticles-carriers bringing the latter to the target cell could be employed. N-type and p-type Si semiconductor nanoparticles, to control adhesion of VLP were applied. Optical absorbance spectra and electron microscopy evidenced that VLP became connected to Si nanoparticles. Moreover, a density of the adhered VLP depended on the type of both semiconductor and VLP.
Self-Assembled System of Semiconductor and Virus Like Nanoparticles
2009
Virus like nanoparticles (VLP) are in use to be absorbed by cells to cause biological effects. To increase a local concentration of VLP, nanoparticles-carriers bringing the latter to the target cell could be employed. N-type and p-type Si semiconductor nanoparticles, to control adhesion of VLP were applied. Optical absorbance spectra and electron microscopy evidenced that VLP became connected to Si nanoparticles. Moreover, a density of the adhered VLP depended on the type of both semiconductor and VLP.
Long-wavelength monolithic GaInNAs vertical-cavity optical amplifiers
2004
We report on the continuous-wave amplification characteristics of an optically pumped 1.3-μm multiple-quantum-well GaInNAs-GaAs vertical-cavity semiconductor optical amplifier (VCSOA). The VCSOA structure was monolithically grown by molecular beam epitaxy and operated in reflection mode in a fiber-coupled system. The maximum on-chip gain attained, limited by the onset of laser action, was 15.6 dB at 196 mW of 980-nm pump power. For a chip gain of 10.4 dB, the optical bandwidth was 10.8 GHz and the saturation output power was -9 dBm. By varying the pump laser power, a maximum extinction ratio of 22.3 dB was obtained. Temperature-controlled tuneable operation of the device is also presented a…
Optimization of semiconductor halide perovskite layers to implement waveguide amplifiers
2017
Semiconductor organometallic halide (CH 3 NH 3 PbX 3 , X=Cl, Br, I) perovskites (HPVK) have been emerged as a potential gain media to construct a new generation of active photonic devices. Indeed, during the last three years a significant effort has been carried out to implement HPVK-based optical amplifiers or lasers with improved quality factors. In particular, minimization of the threshold of stimulated emission has been an important concern to decrease the power consumption, and hence to enhance the performances of the device. For this purpose strategies include a suitable integration of the semiconductor in a photonic structure, or the optimization of the material. Here we propose a no…
GaInNAs/GaAs Bragg-mirror-based structures for novel 1.3μm device applications
2004
We report the use of GaInNAs/GaAs material system for a range of 1.3 μm vertical-cavity devices namely VCSELs, VCSOAs, VECSELs and SESAMs. Using optical pumping, we demonstrate that up to 4 mW of 1290 nm output power can be fibre-coupled from a VCSEL. We also show that tayloring the VCSEL structure allows to produce a monolithic long-wavelength VCSOA with up to 16 dB of gain. We also report the first demonstration of a 1.3 μm VECSEL with more than 0.5 W of CW ouptut power. Finally, annealing effects on the properties of a GaInNAs SBR and modelocking of two Nd:doped solid state lasers using this element are described.
Halide perovskite amplifiers integrated in polymer waveguides
2016
Semiconductor organometallic halide perovskites (CH 3 NH 3 PbX 3 , X=Cl, Br, I) (HPVK) have emerged as a new promising material able to improve the optoelectronic technology performance. Although this material has mostly been applied to improve the efficiency of photovoltaic devices, it also shows amazing properties for photonic applications. In particular, HPVK exhibits high photoluminescence (PL) quantum yield (up to 70%) at room temperature together with a tunable band-gap controlled by its chemical composition. In addition, since HPVKs is deposited in solution at room conditions, it can be easily incorporated in different photonic structures to efficiently exploit its emission propertie…
Absorption Properties of Metal–Semiconductor Hybrid Nanoparticles
2011
The optical response of hybrid metal-semiconductor nanoparticles exhibits different behaviors due to the proximity between the disparate materials. For some hybrid systems, such as CdS-Au matchstick-shaped hybrids, the particles essentially retain the optical properties of their original components, with minor changes. Other systems, such as CdSe-Au dumbbell-shaped nanoparticles, exhibit significant change in the optical properties due to strong coupling between the two materials. Here, we study the absorption of these hybrids by comparing experimental results with simulations using the discrete dipole approximation method (DDA) employing dielectric functions of the bare components as input…
<title>Spin-polarized electron kinetics under high-intensity picosecond excitation</title>
2003
ABSTRACT Spin-polarized electron kinetics is studied by time-resolved polarized photoemission with picosecond resolution. The re-sponse time of strained layer photocathodes is found to be in a range of a few picosecond offering an ultrafast response andhigh spin-polarization of emitted electrons. The studies of the sub-picosecond spin dynamics are facilitated in high-intensityexcitation regime when the length of the emission pulse is enlarged due to the dispersion of acceleration time and Coulombrepulsion ofthe electrons in their flight in the vacuum.Keywords: optical orientation, spin kinetics, strained semiconductor layer, time-resolved emission. 1. INTRODUCTION GaAs, layers are known to …