scholarly journals Time-Resolved In Situ Spectroscopy During Formation of the GaP/Si(100) Heterointerface

2015 ◽  
Vol 6 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Oliver Supplie ◽  
Matthias M. May ◽  
Gabi Steinbach ◽  
Oleksandr Romanyuk ◽  
Frank Grosse ◽  
...  
Keyword(s):  
In Situ Spectroscopy ◽  
Time Resolved

scholarly journals Space- and Time-Resolved In-situ Spectroscopy on the Coke Formation in Molecular Sieves: Methanol-to-Olefin Conversion over H-ZSM-5 and H-SAPO-34

2008 ◽  
Vol 14 (36) ◽  
pp. 11320-11327 ◽  
Author(s):  
Davide Mores ◽  
Eli Stavitski ◽  
Marianne H. F. Kox ◽  
Jan Kornatowski ◽  
Unni Olsbye ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Coke Formation ◽  
In Situ Spectroscopy ◽  
Time Resolved ◽  
Space And Time ◽  
Olefin Conversion ◽  
Methanol To Olefin

Exciton dynamics in thick GaN MOVPE epilayers deposited on sapphire.

1997 ◽  
Vol 2 ◽  
Author(s):  
J. Allègre ◽  
P. Lefebvre ◽  
J. Camassel ◽  
B. Beaumont ◽  
Pierre Gibart
Keyword(s):  
Layer Thickness ◽  
Buffer Layers ◽  
Rate Equations ◽  
Time Resolved ◽  
Versus Layer ◽  
Level Model ◽  
Shallow Impurities ◽  
Aln Buffer ◽  
Time Resolved Photoluminescence

Time-resolved photoluminescence spectra have been recorded on three GaN epitaxial layers of thickness 2.5 μm, 7 μm and 16 μm, at various temperatures ranging from 8K to 300K. The layers were deposited by MOVPE on (0001) sapphire substrates with standard AlN buffer layers. To achieve good homogeneities, the growth was in-situ monitored by laser reflectometry. All GaN layers showed sharp excitonic peaks in cw PL and three excitonic contributions were seen by reflectivity. The recombination dynamics of excitons depends strongly upon the layer thickness. For the thinnest layer, exponential decays with τ ~ 35 ps have been measured for both XA and XB free excitons. For the thickest layer, the decay becomes biexponential with τ1 ~ 80 ps and τ2 ~ 250 ps. These values are preserved up to room temperature. By solving coupled rate equations in a four-level model, this evolution is interpreted in terms of the reduction of density of both shallow impurities and deep traps, versus layer thickness, roughly following a L−1 law.

Monitoring Polymer-Assisted Mechanochemical Cocrystallisation Through in Situ X-Ray Powder Diffraction

2020 ◽  
Author(s):  
Luzia S. Germann ◽  
Sebastian T. Emmerling ◽  
Manuel Wilke ◽  
Robert E. Dinnebier ◽  
Mariarosa Moneghini ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Powder Diffraction ◽  
Reaction Rate ◽  
Polymer Additives ◽  
Time Resolved ◽  
X Ray

Time-resolved mechanochemical cocrystallisation studies have so-far focused solely on neat and liquid-assisted grinding. Here, we report the monitoring of polymer-assisted grinding reactions using <i>in situ</i> X-ray powder diffraction, revealing that reaction rate is almost double compared to neat grinding and independent of the molecular weight and amount of used polymer additives.<br>

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

Dependence of the intrinsic phase structure of Bi2O3 catalysts on photocatalytic CO2 reduction

2021 ◽  
Vol 11 (6) ◽  
pp. 2021-2025
Author(s):  
Liujin Wei ◽  
Guan Huang ◽  
Yajun Zhang
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Phase Structure ◽  
Co2 Reduction ◽  
Fourier Transform Infrared ◽  
Time Resolved ◽  
Dependent Activity

The combination of time-resolved transient photoluminescence with in-situ Fourier transform infrared spectroscopy has been conducted to investigate the intrinsic phase structure-dependent activity of Bi2O3 catalyst for CO2 reduction.

The electron-transfer intermediates of the oxygen evolution reaction (OER) as polarons by in situ spectroscopy

2021 ◽  
Author(s):  
Hanna Lyle ◽  
Suryansh Singh ◽  
Michael Paolino ◽  
Ilya Vinogradov ◽  
Tanja Cuk
Keyword(s):  
Electron Transfer ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Catalytic Reactions ◽  
In Situ Spectroscopy ◽  
Chemical Bonds

The conversion of diffusive forms of energy (electrical and light) into short, compact chemical bonds by catalytic reactions regularly involves moving a carrier from an environment that favors delocalization to one that favors localization.

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