The nucleation and growth mechanisms of graphene on Rh(111) via temperature-programmed growth of C(2)H(4) are studied by scanning tunneling microscopy and spectroscopy, and by density functional theory calculations. By combining our experimental and first-principles approaches, we show that carbon nanoislands form in the initial stages of graphene growth, possessing an exclusive size of seven h...

The nature of the lowest-energy electronic excitations in prototypical molecular solids is studied here in detail by combining electron energy loss spectroscopy (EELS) experiments and state-of-the-art many-body calculations based on the Bethe–Salpeter equation. From a detailed comparison of the spectra in picene, coronene and tetracene we generally find a good agreement 8 Authors to whom any co...

In this talk, we present our studies on recent discovered polycyclic aromatic hydrocarbon (PAH) superconductors including alkali-metaldoped picene (C22H14), coronene (C24H12), phenanthrene (C14H10), and dibenzopentacene (C30H18), which might provide route to high Tc superconductors and give hints on novel pairing mechanisms. Systematic computer simulations were carried out so to gain understand...

Abstract Graphene nano-flakes (GNFs) are predicted to host spin-polarized metallic edge states, which envisioned for exploration of spintronics at the nanometer scale. To date, experimental realization GNFs is only in its infancy because limitation precise cutting or synthesizing methods Here, we use low temperature scanning tunneling microscope manipulate coronene molecules on a Cu(111) surfac...

Hydrogen plays important roles in the on-surface synthesis of carbon-based materials ultra-high vacuum. The complex interplay between hydrogen and surface-adsorbed polycyclic aromatic hydrocarbons (PAHs) is tracked by situ time-of-flight secondary ion mass spectrometry (ToF-SIMS) combined with isotope labeling. In deuterium labeling prototypical PAHs, coronene (CR) 7-armchair graphene nanoribbo...

The far-IR characteristics of astrophysically relevant polycyclic aromatic hydrocarbons (PAHs) averaging in size around 100 carbon atoms have been studied using the theoretical spectra in the NASA Ames PAH IR Spectroscopic Database. These spectra were calculated using density functional theory. Selections of PAH species are made, grouped together by common characteristics or trends, such as siz...