Competitive chemisorption of bifunctional carboxylic acids on H:Si(100): A first-principles study

We investigate competitive chemisorption processes of bifunctional alpha-carboxy omega-alkenes and omega-alkynes on fully hydrogenated H:Si(100), using first-principles density functional theory, in extended surface simulations. We study the structural properties and quantify the energetics and activation barriers, analyzing the reaction paths. Our results reveal that, if the plain, unactivated chemisorption reaction is always achieved through high barriers, once realized the configurations are very stable, ensuring robustness and reliability of the functionalized interface. We identify the conditions where disordered configurations are more likely to arise, with both functionalities offered at the free surface. For all stable configurations, a thorough analysis of the electronic properties and the extent of hybridization in the functionalized interface allows us to identify promising candidates for applications in molecular electronics.