The on surface synthesis of a two-dimensional (2D) covalent organic framework from halogenated aromatic monomer under ultra-high vacuum conditions is shown to be dependent the choice substrate.

Developing efficient catalysts for electrolysis, in particular the oxygen evolution anodic half cell reaction, is an important challenge energy conversion technologies. By taking inspiration from catalytic properties of single-atom and metallo-proteins, we exploit potential metal–organic networks as electrocatalysts reaction (OER). A dramatic enhancement activity toward production by nearly 2 orders magnitude demonstrated novel heterobimetallic organic compared to metallo-porphyrins. Using a...

Organic oligomers and polymers with extended π-conjugation are the fundamental building blocks of organic electronic devices. Novel routes being explored to create tailor-made materials, recent progress in chemistry surface has led synthesis planar 2D polymers. Here we show how extending second dimension leads novel materials HOMO–LUMO gaps smaller than 1D built from same parent molecular repeat unit. Density functional theory calculations on experimentally realized grant insight into gap...

We present a variable-temperature study of monolayer self-assembly at the liquid−solid interface. By means in situ scanning tunneling microscopy (STM), reversible phase transitions from nanoporous low-temperature to more densely packed high-temperature are observed. The occurrence transition and respective temperature were found depend on type solvent solute concentration. Estimates entropic cost enthalpic gain upon suggest that coadsorption molecules within cavities structure renders this...

Adsorption of the brominated aromatic molecule 1,3,5-tris(4-bromophenyl)benzene on different metallic substrates, namely Cu(111), Ag(111), and Ag(110), has been studied by variable-temperature scanning tunneling microscopy (STM). Depending substrate temperature, material, crystallographic orientation, a surface-catalyzed dehalogenation reaction is observed. Deposition onto catalytically more active substrates Cu(111) Ag(110) held at room temperature leads to cleavage carbon−bromine bonds...

We report the synthesis and first electronic characterization of an atomically thin two dimensional π-conjugated polymer. Polymerization via Ullmann coupling a tetrabrominated tetrathienoanthracene on Ag(111) in ultra-high vacuum (UHV) produces porous 2D polymer network that has been characterized by scanning tunnelling microscopy (STM). High-resolution X-ray photoelectron spectroscopy (HRXPS) shows reaction proceeds distinct steps: dehalogenation brominated precursor, which begins at room...

The distinct stacking behaviour of two related 2D covalent organic frameworks is traced back to geometric and electronic features their building blocks. Self-complementarity donor–acceptor-type interactions are identified as design principles access highly crystalline COFs.

Two-dimensional molecular self-assembly at the liquid/solid interface is a widely employed approach in surface science to pattern surfaces nanometre scale. A multitude of supramolecular structures can be realized depending on parameters such as functionalization building blocks, temperature which takes place, type solvent and solute concentration. How these other influence kinetics thermodynamics process subject this review.

Weak interactions between bromine, sulphur, and hydrogen are shown to stabilize 2D supramolecular monolayers at the liquid–solid interface. Three different thiophene-based semiconducting organic molecules assemble into close-packed ultrathin ordered layers. A combination of scanning tunneling microscopy (STM) density functional theory (DFT) elucidates within monolayer. Electrostatic identified as driving force for intermolecular Br⋯Br Br⋯H bonding. We find that S⋯S layers correlate with hole...

We report the synthesis of extended two-dimensional organic networks on Cu(111), Ag(111), Cu(110), and Ag(110) from thiophene-based molecules. A combination scanning tunnelling microscopy X-ray photoemission spectroscopy yields insight into reaction pathways single molecules towards formation organometallic polymeric structures via Ullmann dehalogenation C-C coupling. The thermal stability molecular is probed by annealing at elevated temperatures up to 500 °C. On Cu(111) only are formed,...

The catalytic synergy between cobalt oxide and gold leads to strong promotion of the oxygen evolution reaction (OER)-one half-reaction electrochemical water splitting. However, mechanism behind enhancement effect is still not understood, in part due a missing structural model active interface. Using novel interplay cyclic voltammetry (CV) for electrochemistry integrated with scanning tunneling microscopy (STM) X-ray photoelectron spectroscopy (XPS) on an atomically defined oxide/Au(111)...

Metal-organic supramolecular chemistry on surfaces has matured to a point where its underlying growth mechanisms are well understood and structures of defined coordination environments metal atoms can be synthesized in controlled reproducible procedure. With surface-confined molecular self-assembly, scientists have tool box at hand which used prepare with desired properties, as for example oxidation number spin state the transition within organic matrix. From structural view, these sites...

We report the formation of highly-ordered self-assembled monolayers an achiral organic semiconductor molecule. STM results show spontaneous very large single domains ordered chiral monolayers. DFT calculations support identification halogen bonds as primary interactions that steer molecular self-assembly, leading to organizational chirality.

Conjugated polymers find widespread application in (opto)electronic devices, sensing, and as catalysts. Their common one-dimensional structure can be extended into the second dimension to create conjugated planar sheets of covalently linked molecules. Extending π-conjugation unlocks a new class semiconductive which consequence their unique electronic properties usability numerous applications. In this article theoretical band structures set 2D are compared information on important...

The sequence of a peptide programs its self-assembly and hence the expression specific properties through non-covalent interactions. A large variety nanostructures has been designed employing different aspects these interactions, such as dispersive hydrogen bonding or ionic Here we demonstrate sequence-controlled fabrication molecular using peptides bio-organic building blocks for two-dimensional (2D) self-assembly. Scanning tunnelling microscopy reveals changes from compact linear...

Abstract Big sets of experimental data are key to assess statistical device performance and distill underlying trends. This insight, in turn, can then be used improve on the fabrication process. We here describe a standardized optimized inline process present analysis tens thousands cells with chalcopyrite‐type Cu(In,Ga)Se 2 absorber. The large number samples allows us point out where Ag alloying into absorber offers improvements, how it couples compositional optoelectronic properties. Solar...

Self-assembly and surface-mediated reactions of 1,3,5-tris(4-mercaptophenyl)benzene--a three-fold symmetric aromatic trithiol--are studied on Cu(111) by means scanning tunneling microscopy (STM) under ultrahigh-vacuum (UHV) conditions. In order to reveal the nature intermolecular bonds understand specific role substrate for their formation, these studies were extended Ag(111). Room-temperature deposition onto either yields densely packed trigonal structures with similar appearance lattice...

Polymerization of 1,3,5-tris(4-bromophenyl)benzene via dehalogenation on graphene and hexagonal boron nitride is investigated by scanning tunneling microscopy experiments density functional theory calculations. This work reveals how the interactions between molecules or h-BN grown Ni(111) govern surface-confined synthesis polymers through C-C coupling.

Future combinations of plasmonics with nanometer-sized electronic circuits require strategies to control the electrical excitation plasmons at length scale individual molecules. A unique tool study plasmon ultimate resolution is scanning tunneling microscopy (STM). Inelastic tunnel processes generate in gap that partially radiate into far field where they are detectable as photons. Here we employ STM tris-(phenylpyridine)-iridium complexes on a C60 monolayer, and investigate influence their...

The ability to elucidate the elementary steps of a chemical reaction at atomic scale is important for detailed understanding processes involved, which key uncover avenues improved paths. Here, we track pathway an irreversible direct desulfurization tetracenothiophene adsorbed on Cu(111) closed-packed surface submolecular level. Using precise control tip position in scanning tunneling microscope and electric field applied across tunnel junction, two carbon–sulfur bonds thiophene unit are...

Abstract The chemical and electronic structure of the CdS/(Ag,Cu)(In,Ga)Se 2 (CdS/ACIGSe) interface for thin‐film solar cells, involving an absorber with a bulk [Ag]/([Ag]+[Cu]) (AAC) ratio 0.06, state‐of‐the‐art RbF post‐deposition treatment (PDT), chemical‐bath deposited CdS buffer layer, is studied. To gain detailed depth‐resolved picture CdS/ACIGSe interface, synchrotron‐ laboratory‐based hard X‐ray, soft UV photoelectron spectroscopy, inverse photoemission X‐ray emission spectroscopy...

ABSTRACT This work aims to define the optimization criteria for Cu(In,Ga)Se 2 (CIGS) as a bottom cell in tandem structure, and emphasize differences from optimizing CIGS when operating alone. Reproducing single‐cell recipes only lowering band gap is insufficient optimize cell. We identified that lack of high‐energy photons, which are absorbed by top cell, can cause severe fill factor (FF) loss, thus diminish photovoltaic performance. With nonoptimized buffer layers (CdS ZnMgO), S‐shaped...

Interfacial self-assembly of specific monolayer structures from solution on a graphite surface can be steered by tuning the interplay between solute-solute and solute-solvent interactions.

The optical gap of the organic semiconductor [1]benzothieno[3,2-b]benzothiophene and its 2,7-dibrominated analogue is measured in solution crystalline state by means UV-vis emission spectroscopy. Bromination leads to a change molecular packing from herringbone π-stacked, resulting marked shift absorption spectra which found be accordance with TDDFT calculations.