Technical Physics
Equipment

Equipment

Spectrometer for X-ray photoelectron spectroscopy (XPS)

Ultrahigh vacuum chamber with

  • Photoelectron analyzer (Specs Phoibos 150 with 9 channeltrons)
  • Monochromated X-ray source (Specs Focus 500) for Al Kalpha and Ag Lalpha
  • Electron flood gun for charge compensation
  • Sample manipulator with heater up to 1200 °C
  • Ar-Ion source (sputter gun)
  • LEED optics
  • Ports for evaporators, quartz crystal balance, mass spectrometer, etc.

Typical applications:

  • Analysis of chemical composition of solids, thin films and surfaces
  • Analysis if interfaces between thin films and substrates
  • Electronic and structural properties of surfaces

Si2p spectrum of a H-terminated Si(111) surface.

 

Spectrometer for angle-resolved photoelectron spectroscopy (ARPES)

Ultrahigh vacuum system including an analysis chamber with

  • Photoelectron analyzer (Specs Phoibos 150 with 2D-CCD-Detektor)
  • Monochromated X-ray source (Specs Focus 500) for Al Kalpha and Ag Lalpha
  • UV source (Specs UVS 300) with monochromator (Specs TMM 304) for linear polarised HeI- und HeII-Radiation, polarisation rotatable by 90°
  • 5-axis sample manipulator with liquid He cooling down to ca. 20 K

and a preparation chamber with

  • Sample manipulator with heater uo to ca. 1000 °C und liquid N2 cooling to ca. 100 K
  • Ar-Ion source (sputter gun)
  • LEED optics
  • Ports for evaporators, etc.

Typ. application:

  • Band structure of solids and surfaces
  • Analysis of chemical composition of solids, thin films and surfaces
  • Analysis if interfaces between thin films and substrates
  • Electronic and structural properties of surfaces

Surface state of Au(111). The Rashba splitting is clearly resolved.
(Monochrom. HeI, Epass =5 eV, Tsample=20K)
 

Low-energy electron microscope (LEEM)

System including an analysis chamber with

  • Low-energy electron microscope (Specs FE-LEEM P90)
  • Hg lamp für PEEM
  • UV source für PEEM
  • Sample heating up to ca. 1100 °C

and a preparation chamber with

  • Ar-Ion source (sputter gun)
  • Sample heating up to ca. 1100 °C

Typ. applications:

  • Studies of thin film growth
  • Structural and electronic proerties of surfaces and thin films

(a) LEEM bright filed image (ELEEM = 2.6 eV) of graphene on 4H-SiC(1-100). (b) Typical reflectivity spectra of areas with different thickness. (c) Fals solor image indicating the thickness distribution. From M. Ostler et al., Phys. Rev. B 88 (2013) 085408.
 

High-resolution electron energy loss spectrometer (HREELS)

Ultrahigh vacuum system including an analysis chamber with

  • HREELS spectrometer (Omicron IB500)
  • Sample manipulator with cooling down to ca. 100 K and azimuthal rotation
  • LEED optics
  • Photoelectron analyzer (Omicron EA125)
  • X-ray source for Mg Kalpha (non-monochromatized)

and a preparation chamber with

  • Manipulator with sample heating up to ca. 1100 °C
  • Ar-Ion source (sputter gun)
  • Ports für evaporators, etc.

Typ. applications:

  • Analysis of phonons und plasmons on solid surfaces

Dispersion of the coupled plasmon-phonon mode of bilayer graphene on SiC(0001).
 

Atomic force microscope (AFM)

System including

  • Atomic force microscope (Park Systems XE100) under ambient conditions with optical mikroscope, motorized sample stage and separate z- and x/y-scanners
  • Scanner for max. 5x5 µm2 and max. 100x100 µm2 scan areas
  • Acousting enclosure
  • Active damping of vibrations (Accurion)

Typ. applications:

  • Investigation of structure und morphology of surfaces and thin films

AFM images of a 6H-SiC(0001) surface after hydrogen etching (a) and after subsequent growth of graphene (b).
 

Profilometer

  • Stylus profilometer VEECO Dektak 8

Typ. applications:

  • 2D und 3D maping of surface topographies of samples with up to 200 mm diameter
  • Determination of thin film thickness and deposition rates.

Increase of the thickness of a-C:H films deposited at 2 Pa to 8 Pa with the annealing temperature. From S. Peter et al., Diamond and Relat. Mater. 45 (2014) 43.