Cryogen-free ARPES and High-Resolution XPS Apparatus Spectroscopy X-ray Photoelectron Spectroscope
This is an Angle Resolved PhotoElectron Spectroscopy (ARPES) apparatus, equipped with both ultraviolet (UV) and x-ray sources. It is equipped with a 2D detector electron analyser which allows both the energies and momenta of emitted electrons from the valence band to be measured. This then gives the electronic band dispersion in crystalline solids. The equipment capabilities are:
(a) Ultra-high vacuum, <= 2 x 10E-10 mbar.
(b) Combined energy resolution (electron analyser and UV source) of the system at UV energies is 3 meV.
(c) UV source operates at He I (21.2 eV) and He II (40.8 eV). Capable to use H (10.2 eV), Ne (16.9 eV) and Ar (11.6 eV), with future optical upgrade.
(d) The UV source produces > 2 x 10E16 photons/s.sterad. (e) The combined energy resolution (electron analyser and x-ray source) of the system at x-ray energies is 220 meV.
(f) The x-ray source has a dual anode with Al (1487 eV) and Ag (2984 eV).
(g) The x-ray count rate is 600 kcps at 0.6 eV resolution on the Ag 3d5/2 edge.
(h) The PHOIBOS 150 two-dimensional analyser can measure up to +- 15 degrees simultaneously in angular mode with an angular resolution of < 0.1 degrees and an energy resolution of < 2 meV.
(i) The 5-axis cryo-manipulator is cooled by a closed-cycle compressor and cold finger and provides < 20 K on the sample surface; moreover, polar and azimuth angles are motorized and fully integrated within the analyser control software.
(j) The analysis chamber is equipped with a low energy electron flood gun which results in an effective charge neutralization on a large sample area and allows positively charged insulators or semiconductors to be measured.