Tuning the work function of stepped metal surfaces by adsorption of organic molecules

in Journal of Physics : Condensed Matter (2017), 29

Understanding the binding mechanisms for aromatic molecules on transition-metal surfaces, especially with defects such as vacancies, steps and kinks, is a major challenge in designing functional ... [more ▼]

Understanding the binding mechanisms for aromatic molecules on transition-metal surfaces, especially with defects such as vacancies, steps and kinks, is a major challenge in designing functional interfaces for organic devices. One important parameter in the performance of organic/inorganic devices is the barrier of charge carrier injection. In the case of a metallic electrode, tuning the electronic interface potential or the work function for electronic level alignment is crucial. Here, we use density-functional theory (DFT) calculations with van der Waals (vdW) interactions treated with both screened pairwise (vdWsurf) and many-body dispersion (MBD) methods, to systematically study the interactions of benzene with a variety of stepped surfaces. Our calculations confirm the physisorptive character of Ag(2 1 1), Ag(5 3 3), Ag(3 2 2), Ag(7 5 5) and Ag(5 4 4) surfaces upon the adsorption of benzene. The MBD effects reduce the adsorption energies by about 0.15 eV per molecule compared to the results from the DFT + vdWsurf method. In addition, we find that the higher the step density, the larger the reduction of the work function upon the adsorption of benzene. We also study the effect of vdW interactions on the electronic structure using a fully selfconsistent implementation of the vdWsurf method in the Kohn–Sham DFT framework. We find that the self-consistent vdWsurf effects increase the work function due to the lowered Fermi level and the increased vacuum level. As a result, the benzene/Ag(2 1 1) system has the lowest work function (3.67 eV) among the five adsorption systems, significantly smaller than the work function of the clean Ag(1 1 1) surface (4.74 eV). Our results provide important insights into the stability and electronic properties of molecules adsorbed on stepped metal surfaces, which could help in designing more appropriate interfaces with low work functions for electron transfer. [less ▲]

Tunneling Conductivity in Composites of Attractive Colloids

in Journal of Chemical Physics (2012), 136(164903), 1-5

Turkey declares state of emergency and derogates from ECHR after failed coup d’état

E-print/Working paper (2016)

Turkish migrants and native Germans compared: The effect of inter-ethnic and intra-ethnic friendships on the transition from unemployment to work

in International Migration (2012), 50(1), 39-54

The Turkish State of Emergency Under Turkish Constitutional Law and International Human Rights Law

E-print/Working paper (2017)

Turn up the heat: circulating serotonin tunes our internal heating system.

in Cell metabolism (2015), 21(2), 156-8

Serotonin acts as neurotransmitter in the brain and as a multifaceted signaling molecule coordinating many physiological processes in the periphery. In a recent issue of Nature Medicine, Crane et al ... [more ▼]

Serotonin acts as neurotransmitter in the brain and as a multifaceted signaling molecule coordinating many physiological processes in the periphery. In a recent issue of Nature Medicine, Crane et al. (2014) find that peripheral serotonin controls thermogenesis in adipose tissue by modulating beta-adrenergic stimulation of UCP-1, thereby affecting glucose homeostasis and weight gain. [less ▲]

Turnover Taxes Under State Aid Spotlight

in European Taxation (2019), 59(2/3), 106-112

In response to the Commission’s increasingly broad interpretation of State aid rules with regard to national retail and advertising taxes, in the ANGED cases, the ECJ developed its Distribution Casino ... [more ▼]

In response to the Commission’s increasingly broad interpretation of State aid rules with regard to national retail and advertising taxes, in the ANGED cases, the ECJ developed its Distribution Casino France case law, applying a restrictive view of the qualification of these taxes as illegal State aid. This article provides an overview of the relevant legal questions raised in the ANGED cases, as well as in the Polish and Hungarian retail sales and advertisement tax cases. [less ▲]

Tussen New York en Genève: VN-Kroniek

in Nederlands Tijdschrift voor de Mensenrechten (2023), 48(1),

Deze kroniek informeert over ontwikkelingen met betrekking tot de mensenrechten in de diverse organen van de Verenigde Naties. Daarbij komen zowel de politieke mechanismen (onder meer de Algemene ... [more ▼]

Deze kroniek informeert over ontwikkelingen met betrekking tot de mensenrechten in de diverse organen van de Verenigde Naties. Daarbij komen zowel de politieke mechanismen (onder meer de Algemene Vergadering en de Mensenrechtenraad) aan de orde, als de diverse verdragscomités. [less ▲]

Tussen New York en Genève: VN-Kroniek

in Nederlands Tijdschrift voor de Mensenrechten (2022), 47(3),

Deze kroniek informeert over ontwikkelingen met betrekking tot de mensenrechten in de diverse organen van de Verenigde Naties. Daarbij komen zowel de politieke mechanismen (onder meer de Algemene ... [more ▼]

Deze kroniek informeert over ontwikkelingen met betrekking tot de mensenrechten in de diverse organen van de Verenigde Naties. Daarbij komen zowel de politieke mechanismen (onder meer de Algemene Vergadering en de Mensenrechtenraad) aan de orde, als de diverse verdragscomités. [less ▲]

Tussen Oost en West. De oorlogsherinneringen van migrantenvrouwen en -mannen tijdens de Koude Oorlog

in Wouters, Lisa; Wallemacq, Catherine (Eds.) Aken van het colloquium Genderstudies: een genre apart? Savoirs de genre: quel genre de savoir? (2010)