Weakly interacting systems such as organic molecules on monolayers of hexagonal boron nitride (h-BN) offer the possibility of single integer charge transfer leading to the formation of organic ions. Such open-shell systems exhibit unique optical and electronic properties which differ from their neutral counterparts. In this study, we used a joint experimental and theoretical approach to investigate the charge transfer of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules on h-BN/Ni(111) by using differential reflectance spectroscopy (DRS), scanning tunneling spectroscopy (STS), and photoelectron orbital tomography (POT) measurements in combination with density functional theory (DFT) calculations.
View Article and Find Full Text PDFAim: The aim of this paper is to present the evidence on the effectiveness of non-surgical interventions to improve health and well-being in women living with Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome.
Design: Systematic review guided by Preferred Reporting Items for Systematic Reviews checklist.
Data Sources: The search was conducted between June and September 2022 across the following databases: CINAHL, EMBASE, Medline, PsycINFO and Cochrane.
The adsorption of phthalocyanine (HPc) on the 6H-SiC(0001)-(3 × 3) surface is investigated using X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS), and density functional theory (DFT) calculations. Spectral features are tracked from the submonolayer to the multilayer growth regime, observing a significant modification of spectroscopic signals at low coverage with respect to the multilayer films, where molecules are weakly interacting. Molecules stay nearly flat on the surface at the mono and submonolayers.
View Article and Find Full Text PDFCarbon structures comprising sp 1 chains (e.g., polyynes or cumulenes) can be synthesized by exploiting on-surface chemistry and molecular self-assembly of organic precursors, opening to the use of the full experimental and theoretical surface-science toolbox for their characterization.
View Article and Find Full Text PDFThe current study generates profound atomistic insights into doping-induced changes of the optical and electronic properties of the prototypical PTCDA/Ag(111) interface. For doping K atoms are used, as KPTCDA/Ag(111) has the distinct advantage of forming well-defined stoichiometric phases. To arrive at a conclusive, unambiguous, and fully atomistic understanding of the interface properties, we combine state-of-the-art density-functional theory calculations with optical differential reflectance data, photoelectron spectra, and X-ray standing wave measurements.
View Article and Find Full Text PDFIntroduction: Childhood malignancy, although a rare phenomenon, is still the leading cause of mortality in the pediatric population. Early diagnosis and treatment are imperative for the achievement of optimal prognosis. The study of factors facilitating the delay in diagnosis is thus of utmost importance, to both shorten the diagnostic delay and allow for early therapeutic intervention, facilitating a higher prognosis.
View Article and Find Full Text PDFWe predict the induction or suppression of magnetism in the valence shell of physisorbed and chemisorbed organic molecules on graphene occurring on the femtosecond time scale as a result of core level excitations. For physisorbed molecules, where the interaction with graphene is dominated by van der Waals forces and the system is non-magnetic in the ground state, numerical simulations based on density functional theory show that the valence electrons relax towards a spin polarized configuration upon excitation of a core-level electron. The magnetism depends on efficient electron transfer from graphene on the femtosecond time scale.
View Article and Find Full Text PDFBeilstein J Nanotechnol
January 2016
By first-principle simulations we study the effects of molecular deformation on the electronic and spectroscopic properties as it occurs for pentacene adsorbed on the most stable site of Al(001). The rationale for the particular V-shaped deformed structure is discussed and understood. The molecule-surface bond is made evident by mapping the charge redistribution.
View Article and Find Full Text PDFAlkali metal atoms are frequently used for simple yet efficient n-type doping of organic semiconductors and as an ingredient of the recently discovered polycyclic aromatic hydrocarbon superconductors. However, the incorporation of dopants from the gas phase into molecular crystal structures needs to be controlled and well understood in order to optimize the electronic properties (charge carrier density and mobility) of the target material. Here, we report that potassium intercalation into the pristine 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) monolayer domains on a Ag(111) substrate induces distinct stoichiometry-dependent structural reordering processes, resulting in highly ordered and large KxPTCDA domains.
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