scholarly journals Efficient hierarchical models for reactivity of organic layers on semiconductor surfaces

2021 ◽  
Vol 42 (12) ◽  
pp. 827-839 ◽  
Author(s):  
Jan‐Niclas Luy ◽  
Mahlet Molla ◽  
Lisa Pecher ◽  
Ralf Tonner
Keyword(s):  
Hierarchical Models ◽  
Semiconductor Surfaces ◽  
Organic Layers

scholarly journals Efficient Hierarchical Models for Reactivity of Organic Layers on Semiconductor Surfaces

2021 ◽  
Author(s):  
Jan-Niclas Luy ◽  
Mahlet Molla ◽  
Lisa Pecher ◽  
Ralf Tonner
Keyword(s):  
Hierarchical Models ◽  
Density Functional ◽  
Semiconductor Surfaces ◽  
Density Functionals ◽  
Functional Theory ◽  
Organic Layers ◽  
Chemical Complexity ◽  
Adsorption Energies ◽  
Reaction Barriers ◽  
Model Reactions

Computational modeling of organic interface formation on semiconductors poses a challenge to a density functional theory-based description due to structural and chemical complexity. A hierarchical approach is presented, where parts of the interface are successively removed in order to increase computational efficiency while maintaining the necessary accuracy. First, a benchmark is performed to probe the validity of this approach for three model reactions and five dispersion corrected density functionals. Reaction energies are generally well reproduced by GGA-type functionals but accurate reaction barriers require the use of hybrid functionals. Best performance is found for the model system that does not explicitly consider the substrate but includes its templating effects. Finally, this efficient model is used to provide coverage dependent adsorption energies and suggest synthetic principles for the prevention of unwanted growth termination reactions for organic layers on semiconductor surfaces.

scholarly journals Efficient Hierarchical Models for Reactivity of Organic Layers on Semiconductor Surfaces

2020 ◽  
Author(s):  
Jan-Niclas Luy ◽  
Mahlet Molla ◽  
Lisa Pecher ◽  
Ralf Tonner
Keyword(s):  
Hierarchical Models ◽  
Density Functional ◽  
Semiconductor Surfaces ◽  
Density Functionals ◽  
Functional Theory ◽  
Organic Layers ◽  
Chemical Complexity ◽  
Adsorption Energies ◽  
Reaction Barriers ◽  
Model Reactions

Computational modeling of organic interface formation on semiconductors poses a challenge to a density functional theory-based description due to structural and chemical complexity. A hierarchical approach is presented, where parts of the interface are successively removed in order to increase computational efficiency while maintaining the necessary accuracy. First, a benchmark is performed to probe the validity of this approach for three model reactions and five dispersion corrected density functionals. Reaction energies are generally well reproduced by GGA-type functionals but accurate reaction barriers require the use of hybrid functionals. Best performance is found for the model system that does not explicitly consider the substrate but includes its templating effects. Finally, this efficient model is used to provide coverage dependent adsorption energies and suggest synthetic principles for the prevention of unwanted growth termination reactions for organic layers on semiconductor surfaces.

scholarly journals Efficient Hierarchical Models for Reactivity of Organic Layers on Semiconductor Surfaces

2020 ◽  
Author(s):  
Jan-Niclas Luy ◽  
Mahlet Molla ◽  
Lisa Pecher ◽  
Ralf Tonner
Keyword(s):  
Hierarchical Models ◽  
Density Functional ◽  
Semiconductor Surfaces ◽  
Density Functionals ◽  
Functional Theory ◽  
Organic Layers ◽  
Chemical Complexity ◽  
Adsorption Energies ◽  
Reaction Barriers ◽  
Model Reactions

Computational modeling of organic interface formation on semiconductors poses a challenge to a density functional theory-based description due to structural and chemical complexity. A hierarchical approach is presented, where parts of the interface are successively removed in order to increase computational efficiency while maintaining the necessary accuracy. First, a benchmark is performed to probe the validity of this approach for three model reactions and five dispersion corrected density functionals. Reaction energies are generally well reproduced by GGA-type functionals but accurate reaction barriers require the use of hybrid functionals. Best performance is found for the model system that does not explicitly consider the substrate but includes its templating effects. Finally, this efficient model is used to provide coverage dependent adsorption energies and suggest synthetic principles for the prevention of unwanted growth termination reactions for organic layers on semiconductor surfaces.

Optical Anisotropy of Organic Layers Deposited on Semiconductor Surfaces

2001 ◽  
Vol 188 (4) ◽  
pp. 1307-1317 ◽  
Author(s):  
T.U. Kampen ◽  
A.M. Paraian ◽  
U. Rossow ◽  
S. Park ◽  
G. Salvan ◽  
...  
Keyword(s):  
Optical Anisotropy ◽  
Semiconductor Surfaces ◽  
Organic Layers

A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

Hierarchical Models of Mood and Anxiety Disorders and the Role of Temperament

2011 ◽  
Author(s):  
D. Ryan Hooper ◽  
Michael J. Ross ◽  
Jillon S. Vander Wal ◽  
Terri L. Weaver
Keyword(s):  
Anxiety Disorders ◽  
Hierarchical Models ◽  
Mood And Anxiety Disorders
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