Exciton localization in MoSe2monolayers induced by adsorbed gas molecules

2019 ◽  
Vol 114 (17) ◽  
pp. 172106 ◽  
Author(s):  
Tommaso Venanzi ◽  
Himani Arora ◽  
Artur Erbe ◽  
Alexej Pashkin ◽  
Stephan Winnerl ◽  
...  
Keyword(s):  
Exciton Localization ◽  
Adsorbed Gas ◽  
Gas Molecules

scholarly journals Monolayer Gas Adsorption on Graphene-Based Materials: Surface Density of Adsorption Sites and Adsorption Capacity

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 423-432
Author(s):  
Olga Jakšić ◽  
Marko Spasenović ◽  
Zoran Jakšić ◽  
Dana Vasiljević-Radović
Keyword(s):  
Surface Density ◽  
Gas Adsorption ◽  
Simple Expression ◽  
Pristine Graphene ◽  
Adsorption Sites ◽  
Adsorbed Gas ◽  
Gas Molecules ◽  
Application Specific ◽  
Analytical Expressions ◽  
Basic Input

Surface density of adsorption sites on an adsorbent (including affinity-based sensors) is one of the basic input parameters in modeling of process kinetics in adsorption based devices. Yet, there is no simple expression suitable for fast calculations in current multiscale models. The published experimental data are often application-specific and related to the equilibrium surface density of adsorbate molecules. Based on the known density of adsorbed gas molecules and the surface coverage, both of these in equilibrium, we obtained an equation for the surface density of adsorption sites. We applied our analysis to the case of pristine graphene and thus estimated molecular dynamics of adsorption on it. The monolayer coverage was determined for various pressures and temperatures. The results are verified by comparison with literature data. The results may be applicable to modeling of the surface density of adsorption sites for gas adsorption on other homogeneous crystallographic surfaces. In addition to it, the obtained analytical expressions are suitable for training artificial neural networks determining the surface density of adsorption sites on a graphene surface based on the known binding energy, temperature, mass of adsorbate molecules and their affinity towards graphene. The latter is of interest for multiscale modelling.

The Influence of the Ambient Gas Environment on the Non-Isothermal DC Electric Measurements in Polymers

2006 ◽  
Vol 514-516 ◽  
pp. 930-934 ◽  
Author(s):  
José N. Marat-Mendes ◽  
Eugen R. Neagu
Keyword(s):  
Polymer Matrix ◽  
Discharge Current ◽  
Charge Trapping ◽  
Polymeric Materials ◽  
Current Method ◽  
Ambient Air ◽  
Humid Air ◽  
Adsorbed Gas ◽  
Thermally Stimulated Discharge Current ◽  
Gas Molecules

The direct current (dc) electric measurements in dielectrics, especially for highly insulating materials, are strongly influenced by the ambient air, mainly by the water vapors contained by the ambient (humid) air which determine a significant increase of the electric conductivity. Beside this, there is a second effect related to the interaction of the absorbed and adsorbed gas molecules with the polymer matrix that modify both the surface and the bulk conductivities. The aim of the paper is to present the influence of the absorbed and/or adsorbed gas molecules on the electric charge trapping and/or detrapping in polyamide 11. The measurements were carried out under ambient (humid) air, in a vacuum at 8 x 10-3 Torr and in dry nitrogen. Because the trapping/detrapping processes and the molecule diffusion process in polymeric materials are slow processes, a variant of the thermally stimulated discharge current method, namely the final thermally stimulated discharge current method and the final isothermal discharge current method have been used in the temperature range from 20 to 190 0C. The absorbed/adsorbed gas molecules into polymer matrix results in a perturbation of the thermodynamic equilibrium and consequently a charge transfer could occur speeding up the deep level charge detrapping.

Microstructure of Gold Films Grown by Ion Induced Deposition

1987 ◽  
Vol 101 ◽  
Author(s):  
J.S. Ro ◽  
A.D. Dubner ◽  
C.V. Thompson ◽  
J. Melngailis
Keyword(s):  
Room Temperature ◽  
Growth Conditions ◽  
Micro Structure ◽  
Adsorbed Gas ◽  
Material Deposition ◽  
Transmission Electron ◽  
Deposition Yield ◽  
Gas Molecules ◽  
The Relationship ◽  
Substrate Temperatures

ABSTRACTA beam of ions incident on a substrate can cause adsorbed gas molecules to break up, resulting in material deposition. We have previously demonstrated deposition of gold from a gas of dimethyl gold hexafluoro acetylacetonate (C7H7F6O2Au) using both focused and broad ion beams. Here we investigate growth at various substrate temperatures and examine micro-structure using transmission electron microscopy. Films grown at room temperature were discontinuous even up to the thickness of 250μπι while films grown at higher substrate temperatures were continuous even at lower thicknesses. Deposition carried out on substrates at 100°C and 160°C using 70 kev Ar+ ions resulted in resistivities approaching the bulk value and a deposition yield of 60 to 75 atoms/ion. The relationship between growth conditions, micro-structure and resistivity will be discussed.

Dielectric Properties of Adsorbed Gas Molecules

1967 ◽  
Vol 46 (11) ◽  
pp. 4381-4386 ◽  
Author(s):  
Oswald Gröbner
Keyword(s):  
Dielectric Properties ◽  
Adsorbed Gas ◽  
Gas Molecules
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