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Updated: Apr 30, 2026

Monolayer Contact Doping of Silicon Surfaces and Nanowires Using Organophosphorus Compounds
Published on: December 2, 2013
A new assisted molecular cycloaddition on boron doped silicon surfaces: a predictive DFT-D study
Khaoula Boukari1, Eric Duverger, Louise Stauffer
1Institut de Science des Matériaux de Mulhouse (IS2M), Université de Haute Alsace, CNRS UMR 7361, 3b rue Alfred Werner, 68093 Mulhouse cedex, France. philippe.sonnet@uha.fr.
Density Functional Theory investigated phthalocyanine molecule adsorption on SiC and silicon-boron surfaces. Boron defects on silicon surfaces significantly influence H2Pc adsorption, enabling novel bonding mechanisms like assisted pseudo cycloaddition.
Area of Science:
- Surface Science
- Computational Chemistry
- Materials Science
Background:
- Phthalocyanine (H2Pc) molecules are crucial in various electronic and catalytic applications.
- Understanding molecule-surface interactions is key to designing advanced materials.
- Silicon carbide (SiC) and boron-doped silicon (SiB) surfaces offer unique electronic properties for adsorption studies.
Purpose of the Study:
- To investigate and compare the adsorption mechanisms of H2Pc molecules on SiC(0001) and SiB surfaces using DFT-D.
- To explore the role of boron defects in modifying the adsorption behavior of H2Pc on SiB surfaces.
- To identify novel adsorption configurations and bonding types.
Main Methods:
- Density Functional Theory with dispersion corrections (DFT-D) was employed for all calculations.
- Adsorption energies and charge transfer were analyzed using Bader charge analysis.
- Geometric structures and bonding configurations were systematically investigated for different surface models.
Main Results:
- On SiC(0001), H2Pc adsorption occurs via a [10+2] cycloaddition mechanism.
- On defectless SiB (SiB-0D), H2Pc does not form chemical bonds due to surface passivation.
- On SiB with two boron defects (SiB-2D), H2Pc adsorption resembles that on SiC.
- On SiB with one boron defect (SiB-1D), an unexpected Si-N bond (Si2-N2) forms, leading to an 'assisted pseudo cycloaddition' adsorption.
Conclusions:
- Boron atoms on SiB surfaces act as electron reservoirs, modulating H2Pc adsorption.
- Surface defects, particularly single boron vacancies, can induce novel chemical bonding pathways for H2Pc.
- The 'assisted pseudo cycloaddition' mechanism offers a new route for designing molecule-surface interactions.
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