scholarly journals Thermal charge carrier driven noise in transmissive semiconductor optics

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
F. Bruns ◽  
S. P. Vyatchanin ◽  
J. Dickmann ◽  
R. Glaser ◽  
D. Heinert ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Semiconductor Optics

Charge Carrier Scattering Mechanisms in Thermoelectric PbTe:Sb

2014 ◽  
Vol 59 (7) ◽  
pp. 706-711 ◽  
Author(s):  
D.M. Freik ◽  
◽  
S.I. Mudryi ◽  
I.V. Gorichok ◽  
R.O Dzumedze ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Scattering Mechanisms ◽  
Carrier Scattering ◽  
Charge Carrier Scattering

The Influence of Nitrogen Position on Charge Carrier Mobility in Enantiopure Aza[6]helicene Crystals

2018 ◽  
Author(s):  
Francesco Salerno ◽  
Beth Rice ◽  
Julia Schmidt ◽  
Matthew J. Fuchter ◽  
Jenny Nelson ◽  
...  
Keyword(s):  
Solid State ◽  
Charge Carrier ◽  
Carrier Mobility ◽  
Chemical Structure ◽  
Crystal Packing ◽  
Charge Carrier Mobility ◽  
Individual Factor ◽  
Charge Mobility ◽  
Order Of Magnitude ◽  
Small Change

<p>The properties of an organic semiconductor are dependent on both the chemical structure of the molecule involved, and how it is arranged in the solid-state. It is challenging to extract the influence of each individual factor, as small changes in the molecular structure often dramatically change the crystal packing and hence solid-state structure. Here, we use calculations to explore the influence of the nitrogen position on the charge mobility of a chiral organic molecule when the crystal packing is kept constant. The transfer integrals for a series of enantiopure aza[6]helicene crystals sharing the same packing were analysed in order to identify the best supramolecular motifs to promote charge carrier mobility. The regioisomers considered differ only in the positioning of the nitrogen atom in the aromatic scaffold. The simulations showed that even this small change in the chemical structure has a strong effect on the charge transport in the crystal, leading to differences in charge mobility of up to one order of magnitude. Some aza[6]helicene isomers that were packed interlocked with each other showed high HOMO-HOMO integrals (up to 70 meV), whilst molecules arranged with translational symmetry generally afforded the highest LUMO-LUMO integrals (40 - 70 meV). As many of the results are not intuitively obvious, a computational approach provides additional insight into the design of new semiconducting organic materials.</p>

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

2019 ◽  
Author(s):  
Subhajit Bhattacharjee ◽  
Sonu Pratap Chaudhary ◽  
Sayan Bhattacharyya
Keyword(s):  
Charge Carrier ◽  
Wide Spectrum ◽  
Real Life ◽  
Metal Halide ◽  
Lead Free ◽  
Water Medium ◽  
Type I ◽  
Type Ii ◽  
Perovskite Layer ◽  
Halide Perovskites

<p>Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs<sub>3</sub>Bi<sub>2</sub>X<sub>9 </sub>(X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag<sub>2</sub>S and perovskite/TiO<sub>2 </sub>composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag<sub>2</sub>S and TiO<sub>2</sub> coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>/Ag<sub>2</sub>S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications. </p>

Charge Carrier Dynamics in Nanostructured Tungsten Trioxide for Solar Driven Water Oxidation

2018 ◽  
Author(s):  
Sacha Corby ◽  
Laia Francas ◽  
Shababa Selim ◽  
Michael Sachs ◽  
Andreas Kafizas ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Water Oxidation ◽  
Tungsten Trioxide ◽  
Carrier Dynamics ◽  
Charge Carrier Dynamics

Anisotropic Charge Carrier Diffusion Correlated to Ferroelastic Twin Domains in MAPbI3 Perovskite

2019 ◽  
Author(s):  
Ilka M. Hermes ◽  
Andreas Best ◽  
Julian Mars ◽  
Sarah M. Vorpahl ◽  
Markus Mezger ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Diffusion ◽  
Charge Carrier Diffusion

Limits of Charge Carrier Transport in Halide Perovskites Revealed by Optical-Pump Terahertz-Probe Spectroscopy

2019 ◽  
Author(s):  
Hannes Hempel ◽  
Andrei Petsiu ◽  
Martin Stolterfoht ◽  
Pascal Becker ◽  
Dieter Neher ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Transport ◽  
Charge Carrier Transport ◽  
Optical Pump ◽  
Halide Perovskites ◽  
Probe Spectroscopy

Thermal Frequency Imaging: A New Application of Laser Voltage Imaging Applied on 40nm Technology

2011 ◽  
Author(s):  
Guillaume Celi ◽  
Sylvain Dudit ◽  
Thierry Parrassin ◽  
Philippe Perdu ◽  
Antoine Reverdy ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Laser Beam ◽  
Integrated Circuit ◽  
Carrier Density ◽  
Deep Submicron ◽  
Charge Carrier Density ◽  
Voltage Imaging ◽  
A New Technique ◽  
Scan Chain

Abstract For Very Deep submicron Technologies, techniques based on the analysis of reflected laser beam properties are widely used. The Laser Voltage Imaging (LVI) technique, introduced in 2009, allows mapping frequencies through the backside of integrated circuit. In this paper, we propose a new technique based on the LVI technique to debug a scan chain related issue. We describe the method to use LVI, usually dedicated to frequency mapping of digital active parts, in a way that enables localization of resistive leakage. Origin of this signal is investigated on a 40nm case study. This signal can be properly understood when two different effects, charge carrier density variations (LVI) and thermo reflectance effect (Thermal Frequency Imaging, TFI), are taken into account.

Strong Coupling of Electron and Nuclear Spins: Outlook and Prospects

2018 ◽  
Author(s):  
M. M. Glazov
Keyword(s):  
Energy Spectrum ◽  
Charge Carrier ◽  
Strong Coupling ◽  
Nuclear Spin ◽  
Spin Dynamics ◽  
Spin Polaron ◽  
Nuclear Spins ◽  
Deep Impurity ◽  
Impurity Centers ◽  
Ordered State

In this chapter, some prospects in the field of electron and nuclear spin dynamics are outlined. Particular emphasis is put ona situation where the hyperfine interaction is so strong that it leads to a qualitative rearrangement of the energy spectrum resulting in the coherent excitation transfer between the electron and nucleus. The strong coupling between the spin of the charge carrier and of the nucleus is realized, for example in the case of deep impurity centers in semiconductors or in isotopically purified systems. We also discuss the effect of the nuclear spin polaron, that is ordered state, formation at low enough temperatures of nuclear spins, where the orientation of the carrier spin results in alignment of the spins of nucleus interacting with the electron or hole.

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