Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror.

Realizing plasmonic nanogaps with a refractive index ( = 1) environment in metallic nanoparticle (NP) structures is highly attractive for a wide range of applications. So far in self-assembly-based approaches, without surface functionalization of metallic NPs, achieving such extremely small nanogaps is challenging. Surface functionalization introduces changes in the refractive index at nanogaps, which in turn deteriorates the desired plasmonic properties.

DFT-Assisted Investigation of the Electric Field and Charge Density Distribution of Pristine and Defective 2D WSe by Differential Phase Contrast Imaging.

Most properties of solid materials are defined by their internal electric field and charge density distributions which so far are difficult to measure with high spatial resolution. Especially for 2D materials, the atomic electric fields influence the optoelectronic properties. In this study, the atomic-scale electric field and charge density distribution of WSe bi- and trilayers are revealed using an emerging microscopy technique, differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM).

Defect-Assisted Exciton Transfer across the Tetracene-Si(111):H Interface.

Exciton transfers are ubiquitous and extremely important processes, but often poorly understood. A recent example is the triplet exciton transfer in tetracene sensitized silicon solar cells exploited for harvesting high-energy photons. The present ab initio molecular dynamics calculations for tetracene-Si(111):H interfaces show that Si dangling bonds, intuitively expected to hinder the exciton transfer, actually foster it.

Electron-Nuclear Coherent Coupling and Nuclear Spin Readout through Optically Polarized V Spin States in hBN.

Coherent coupling of defect spins with surrounding nuclei along with the endowment to read out the latter are basic requirements for an application in quantum technologies. We show that negatively charged boron vacancies (V) in hexagonal boron nitride (hBN) meet these prerequisites. We demonstrate Hahn-echo coherence of the V spin with a characteristic decay time = 15 μs, close to the theoretically predicted limit of 18 μs for defects in hBN.

Adatom mediated adsorption of N-heterocyclic carbenes on Cu(111) and Au(111).

The adsorption of N-heterocyclic carbenes (NHCs) on Cu(111) and Au(111) surfaces is studied with density-functional theory. The role of the molecular side groups as well as the surface morphology in determining the adsorption geometry are explored in detail. Flat-laying NHCs, as observed experimentally for NHC with relatively small side groups, result from the adsorption at adatoms and give rise to the so-called ballbot configurations, which are more stable than adsorption on flat surfaces and provide an efficient precursor for the formation of bis(NHC) dimers.