Angle-resolved photoemission spectroscopy and imaging with a submicrometre probe at the SPECTROMICROSCOPY-3.2L beamline of Elettra

Abstract

The extensive upgrade of the experimental end-station of the SPECTROMICROSCOPY-3.2L beamline at Elettra synchrotron light source is reported. After the upgrade, angle-resolved photoemission spectroscopy from a submicrometre spot and scanning microscopy images monitoring the photoelectron signal inside selected acquisition angle and energy windows can be performed. As a test case, angle-resolved photoemission spectroscopy from single flakes of highly oriented pyrolitic graphite and imaging of the flakes with image contrast owing to rotation of the band dispersion of different flakes are presented.

Microscopic characterisation of suspended graphene grown by chemical vapour deposition

“…Angle-resolved photoelectron spectroscopy (ARPES) and ccanning photoemission microscopy (SPEM) were carried out at the SpectroMicroscopy beamline at the ELETTRA Synchrotron, Trieste, Italy, where the impinging photon beam is focused with Schwarzschild optics, resulting in a minimum beam diameter of 600 nm, which makes it suitable for submicrometer imaging and spectroscopy 16 . To remove water and contaminants adsorbed during the transfer in air, the samples were annealed in UHV (base pressure 10 −10 mbar) for 45 minutes at a temperature of about 570 K prior to the acquisition of photoemission spectra.…”

Angle-resolved X-ray photoemission electron microscopy

“…We envisage that darkfield XPEEM can be fruitfully applied when imaging inhomogeneous interfaces and polycrystalline surfaces [46], in order to obtain high lateral resolution maps of the electronic band structure. Examples of potential applications range from role of electronic phase separation in complex oxides [47], to electronic effects in graphene flakes [20,21], and to Rashba effect at ferromagnetic surfaces [48].…”

Substrate interactions with suspended and supported monolayerMoS2: Angle-resolved photoemission spectroscopy

“…The first was the Spectromicroscopy Beamline at the Elettra Synchrotron light source [14], which provided scanning photoemission microscopy (SPEM) and micro-ARPES measurements of suspended and supported monolayer MoS 2 . The spectrometer energy resolution of this instrument was set to 100 meV at a 27 eV incident photon energy and with a beam spot size of 1 μm in diameter.…”