The laboratory is devoted to the experimental investigation of the electronic band structure of surfaces and two-dim ensional (2D) materials by means of high-resolution angle-resolved ultraviolet photoelectron spectroscopy (ARPES). The ARPES apparatus, working at high energy and angle resolutions, operating at low temperatures, is contained into an ultra-high-vacuum (UHV) chamber, UHV-connected to a preparation chamber equipped withseveral other characterisation methods and ancillary facilities for samples preparation and 2D materials growth, and is provided with a small UHV chamber for a fast load-lock introduction chamber.
In the following, the main characteristics of the apparatus:
• ARPES hemispherical electron analyser: Scienta SES-200, 4 meV best energy resolution, <0.1◦ angular resolution, 1-50 eV pass-energy range, multi-channel detector (MCD, ±8◦ angular span and 10% of pass-energy energy span);
• ARPES photon source: Omicron-Scienta VUV-5000 monochromatised MW-excited He source, main lines HeIα at 21.218 eV and HeIIα at 40.814 eV, up to HeIIδ at 52.241 eV;
• ARPES manipulator: 5-degrees of freedom UHV manipulator, with precision rotation of the azimuthal and polar angles, cryostat to liquid nitrogen temperature, electron-bombardment heater up to 1200◦C;
• Low-Energy Electron Diffraction (LEED): Specs retractable ErLEED system, with LEED and Auger modules;
• Ion Gun: Omicron ISE10 0.2-5 keV energy range, Ar ion source;
• Mass Spectrometer: residual gas analyser SRS RGA 300, 1-300 a.m.u. range;
• Gas line, equipped with several ports for small bottles and UHV-connected through a leak-valve to the main chamber; oxygen and C2H4 sources mounted, the latter for graphene preparation on metals via temperature programmed growth;
• Organic-molecular beam epitaxy (O-MBE) cells; high-temperature electron-bombardment based evaporator for transition metals; quartz crystal thickness monitor; cleaver, other ancillary facilities for sample preparation, etc.