M. Caputo

Manipulating the Topological Interface by Molecular Adsorbates: Adsorption of Co-Phthalocyanine on Bi2Se3.

Topological insulators are a promising class of materials for applications in the field of spintronics. New perspectives in this field can arise from interfacing metal-organic molecules with the topological insulator spin-momentum locked surface states, which can be perturbed enhancing or suppressing spintronics-relevant properties such as spin coherence. Here we show results from an angle-resolved photemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM) study of the prototypical cobalt phthalocyanine (CoPc)/Bi2Se3 interface. We demonstrate that that the hybrid interface can act on the topological protection of the surface and bury the Dirac cone below the first quintuple layer.

Water Formation for the Metalation of Porphyrin Molecules on Oxidized Cu(111)

Herein the formation of water molecules in the intermediate step of the redox reaction of porphyrins self-metalation on O/Cu(111) is demonstrated. Photoemission measurements show that the temperature on which porphyrins pick-up a substrate metal atom on O/Cu(111) is reduced by about 185±15 K with respect to the pure Cu(111). DFT calculations clearly indicate that the formation of a water molecule is less expensive than the formation of H2 on the O/Cu(111) substrate and, in some cases, it can be also exothermic.

Review of 2H-tetraphenylporphyrins metalation in ultra-high vacuum on metal surfaces

The formation and conformational adaptation of self-assembled monolayer of 2H- tetraphenylporphyrins (2H-TPPs) on metal surfaces, as well as their metalation processes in ultra-high vacuum (UHV), are reviewed. By means of XPS, NEXAFS and STM measurements we demonstrate that, after the annealing at 550 K, a temperature-induced chemical modification of 2H-TPP monolayer on Ag(111) occurs, resulting in the rotation of the phenyl rings parallel to the substrate plane. Moreover, independently of the conformation, we report three dierent methods to metalate 2H-TPP monolayers in UHV. Experimental evidence indicates that the presence of a metal atom in the TPP macrocycle influences both the conformation of the molecule and its adsorption distance.

Electron-hole balanced dynamics in the type-II Weyl semimetal candidate WTe2

M. Caputo, ∗ L. Khalil, 2 E. Papalazarou, N. Nilforoushan, L. Perfetti, Q. D. Gibson, R. J. Cava, and M. Marsi Laboratoire de Physique des Solides, CNRS, Universitè Paris-Sud, Universitè Paris-Saclay, 91405 Orsay Cedex, France UR1-CNRS/Synchrotron SOLEIL, Saint Aubin BP 48, Gif-sur-Yvette F-91192, France Laboratoire des Solides Irradiés, Ecole Polytechnique, CNRS, CEA, Universitè Paris-Saclay, 91128 Palaiseau Cedex, France Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA (Dated: November 15, 2017)

Patterning PEDOT:PSS and tailoring its electronic properties by water-vapour-assisted nanoimprint lithography

We present a new water-vapour-assisted nanoimprint lithography (NIL) process for the patterning of the conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The process was optimized with respect to relative humidity, applied pressure and temperature (RH, p, T). The control of environmental humidity was found to be crucial. High quality nanostructures were reproducibly obtained at high relative humidity values (RH ≳ 75%), with sub-100 nm resolution features attaining aspect ratios as high as ∼6 at ∼95% RH. The developed process of water-vapour-assisted NIL (WVA-NIL) strongly affects the electronic properties of PEDOT:PSS. By current–voltage measurements and ultraviolet photoemission spectroscopy we demonstrate that the process parameters p, T and RH are correlated with changes of PEDOT:PSS conductivity, work function and states of the valence band. In particular, an increase in the films conductivity by factors as high as 105 and a large decrease in the work function, up to 1.5 eV, upon WVA-NIL processing were observed. Employed as an anode buffer layer in P3HT:ICBA bulk heterojunction solar cells, PEDOT:PSS processing was found to affect significantly the device performance.

Time-resolved photoemission ofSr2IrO4

We investigate the temporal evolution of electronic states in strontium iridate

Improved recovery time and sensitivity to H 2 and NH 3 at room temperature with SnO x vertical nanopillars on ITO

{\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}

Electronic structure of Fe3Sion Si(100) substrates

. The time-resolved photoemission spectra of the intrinsic, electron-doped, and hole-doped samples are monitored in identical experimental conditions. Our data on the intrinsic and electron-doped samples, show that doublon-holon pairs relax near to the chemical potential on a time scale shorter than 70 fs. The subsequent cooling of low-energy excitations takes place in two steps: a rapid dynamics of

Electronic structure of Fe3Si on Si(100) substrates

\ensuremath{\cong}120

Electronic structure of Fe{sub 3}Si on Si(100) substrates

fs is followed by a slower decay of