A5013277998- Molecular Junctions and Nanostructures
- Surface Chemistry and Catalysis
- Force Microscopy Techniques and Applications
- Organic Electronics and Photovoltaics
- Surface and Thin Film Phenomena
- Advanced Chemical Physics Studies
- Petroleum Processing and Analysis
- Polymer crystallization and properties
- Thermal and Kinetic Analysis
- Synthesis and Properties of Aromatic Compounds
- Porphyrin and Phthalocyanine Chemistry
- Perovskite Materials and Applications
- Conducting polymers and applications
- Hydrocarbon exploration and reservoir analysis
- Catalysis and Oxidation Reactions
- Photonic Crystals and Applications
- Enhanced Oil Recovery Techniques
- Gas Sensing Nanomaterials and Sensors
- Graphene research and applications
- Carbon Nanotubes in Composites
- Quantum and electron transport phenomena
- Organic Light-Emitting Diodes Research
- Electrochemical Analysis and Applications
- Quantum chaos and dynamical systems
- Advanced biosensing and bioanalysis techniques
King Abdullah University of Science and Technology
2022-2025
Kootenay Association for Science & Technology
2025
IBM Research - Zurich
2015-2022
Universidade Estadual de Campinas (UNICAMP)
2014-2017
University of Basel
2014-2017
Pontifícia Universidade Católica de Campinas
2015
Heavy oil molecular mixtures were investigated on the basis of single molecules resolved by atomic force microscopy. The eight different samples analyzed include asphaltenes and other heavy fractions geographic/geologic origin processing steps applied. collected AFM data individual provide information about geometry, aromaticity, content nonhexagonal rings, typical types locations heterocycles, occurrence, length connectivity alkyl side chains, ratio archipelago- vs island-type...
Abstract Indenofluorenes are non-benzenoid conjugated hydrocarbons that have received great interest owing to their unusual electronic structure and potential applications in nonlinear optics photovoltaics. Here we report the generation of unsubstituted indeno[1,2- a ]fluorene on various surfaces by cleavage two C–H bonds 7,12-dihydroindeno[1,2- through voltage pulses applied tip combined scanning tunnelling microscope atomic force microscope. On bilayer NaCl Au(111), is neutral charge...
High-resolution atomic force microscopy fingerprints of alkyl and cycloaliphatic moieties were obtained on tailor-made hydrocarbon model compounds.
Controlling selectivity of reactions is a quest in chemistry. Here, we demonstrate reversible and selective bond formation dissociation promoted by tip-induced reduction-oxidation on surface. Molecular rearrangements leading to different constitutional isomers are selected the polarity magnitude applied voltage pulses from tip combined scanning tunneling atomic force microscope. Characterization dependence determination reaction rates isomerization provide insight into underlying mechanisms....
We report the on-surface synthesis of a nonbenzenoid triradical through dehydrogenation truxene (C27H18) on coinage metal and insulator surfaces. Voltage pulses applied via tip combined scanning tunneling microscope/atomic force microscope were used to cleave individual C-H bonds in truxene. The resultant final product truxene-5,10,15-triyl (1) was characterized at single-molecule scale using combination atomic microscopy, spectroscopy. Our analyses show that 1 retains its open-shell quartet...
Abstract The self‐aligned gate (SAG) transistor architecture is attractive for electronic circuit applications due to its enabling attributes, including low parasitic capacitances and higher frequency operation. However, SAG transistors often rely on complex manufacturing, which limits their practical utilization. Herein, we overcome this bottleneck demonstrate organic in the source/drain (S/D) electrodes are separated by (G) terminal with sub‐20 nm gaps. eliminates overlaps while minimizing...
Solution-processed high-performing ambipolar organic phototransistors (OPTs) can enable low-cost integrated circuits. Here, a heteroatom engineering approach to modify the electron affinity of low band gap diketopyrrolopyrole (DPP) co-polymer, resulting in well-balanced charge transport, more preferential edge-on orientation and higher crystallinity, is demonstrated. Changing comonomer from sulfur (benzothiadiazole (BT)) oxygen (benzooxadiazole (BO)) leads an increased introduces...
The formation of on-surface coordination polymers is controlled by the interplay chemical reactivity and structure building blocks, as well orientating role substrate registry. Beyond predetermined patterns structural assembly, reactants involved may provide alternative pathways in their aggregation. Organic molecules, which are transformed a surface reaction, be subsequently trapped via homo- or heterometal adatoms, also play molecular transformation. amino-functionalized perylene...
Abstract The field of molecular electronics aims at using single molecules as functional building blocks for components, such switches, rectifiers or transistors. A key challenge is to perform measurements with atomistic control over the alignment molecule and its contacting electrodes. Here we use atomic force microscopy examine charge transfer between weakly coupled pentacene on insulating films single-electron sensitivity details. We show that, in addition imaging capability, probe tip...
Visualizing molecular charging High-resolution atomic force microscopy (AFM) has been used to control and image the charge state of organic molecules adsorbed on multilayer sodium chloride films. Fatayer et al. biased an AFM probe tip with a voltage discharge such as azobenzene porphine from cations anions. Subsequent imaging carbon monoxide–functionalized tips revealed changes in conformation, bond order, aromaticity resulting charge-state changes. Science , this issue p. 142
Improving hole injection through the surface modification of indium tin oxide (ITO) with self-assembled monolayers (SAMs) is a promising method for modulating carrier in organic light-emitting diodes (OLEDs). However, developing SAMs required characteristics remains daunting challenge. Herein, we functionalize ITO various phosphonic acid and evaluate SAM-modified anodes terms their work function (WF), molecular distribution, coverage, electrical conductivity. We fabricate characterize green...
Laser-scribed graphene electrodes (LSGEs) are promising platforms for the development of electrochemical biosensors point-of-care settings and continuous monitoring wearable applications. However, frequent occurrence biofouling drastically reduces sensitivity selectivity these devices, hampering their sensing performance. Herein, we describe a versatile, low-impedance, robust antibiofouling interface based on sulfobetaine-zwitterionic moieties. The induces formation hydration layer exerts...
A deep understanding of how solution-processed solar cells (SSCs) perform under varying temperatures and irradiance is crucial for their optimal design, synthesis, use. However, current partial spectral characterization, primarily below the band gap wavelengths (λ < λg), limits insights into full operation. In this work, we expand knowledge by providing comprehensive full-spectrum experimental optical characterizations (∼300-2500 nm) theoretical optical-thermal-electrical analysis most...
This study addresses the effect of sample preparation conditions on structural integrity and composition heavy hydrocarbon mixtures imaged by noncontact atomic force microscopy (nc-AFM). We designed prepared a set organic molecules mimicking well-accepted key characteristics oil asphaltenes including molecular architecture, weight, boiling point, H/C ratio, bond strength. deliberately focused multicore molecule structures with long aliphatic linkers as this architecture was largely absent in...
The initial thermal reactions of aromatic hydrocarbons are relevant to many industrial applications. However, tracking the growing number heavy polycyclic hydrocarbon (PAH) products is extremely challenging because unfolding in parallel from a mixture molecules. Herein, we studied 2,7-dimethylpyrene (DMPY) decipher roles methyl substituents during mild treatment. We found that presence key for reducing severity required initiate chemical natural molecular mixtures. A complex including...
Abstract Dissolved organic carbon (DOC) is the largest pool of exchangeable in ocean. However, less than 10% DOC has been molecularly characterized deep ocean to understand DOC's recalcitrance. Here we analyze radiocarbon ( 14 C) depleted, and presumably refractory, low molecular weight (LMW) from North Central Pacific using atomic force microscopy produce first atomic‐resolution images individual LMW molecules. We evaluate surface chemical structures context their relative persistence...
Here we present a new method that integrates atomic force microscopy (AFM) with analytical tools such as high-performance liquid chromatography (HPLC) diode-array ultraviolet–visible (UV) absorbance, and mass spectrometry (MS) along synthetic chemistry. This allows the detection, identification, quantification of novel polycyclic aromatic hydrocarbons (PAH) in complex molecular mixtures. multidisciplinary methodology is employed to characterize supercritical pyrolysis products n-decane,...
Abstract Condensation processes are of key importance in nature and play a fundamental role chemistry physics. Owing to size effects at the nanoscale, it is conceptually desired experimentally probe dependence condensate structure on number constituents one by one. Here we present an approach study condensation process atom-by-atom with scanning tunnelling microscope, which provides direct real-space access atomic precision aggregates formed atomically defined ‘quantum boxes’. Our analysis...
We report the generation of a non-benzenoid polycyclic conjugated hydrocarbon, which consists biphenyl moiety substituted by indenyl units at 4,4' positions, on ultra-thin sodium chloride films tip-induced chemistry. Single-molecule characterization scanning tunneling and atomic force microscopy reveals an open-shell biradical ground state, with peculiar electronic configuration wherein singly-occupied molecular orbitals (SOMOs) are lower in energy than highest occupied orbital (HOMO).
We report the generation of a nonbenzenoid polycyclic conjugated hydrocarbon, which consists biphenyl moiety substituted by indenyl units at 4,4′ positions, on ultrathin sodium chloride films tip-induced chemistry. Single-molecule characterization scanning tunneling and atomic force microscopy reveals an open-shell biradical ground state with peculiar electronic configuration wherein singly occupied molecular orbitals (SOMOs) are lower in energy than highest orbital (HOMO).