Laboratory for Surface Diagnostics

The pro­per­ties of ma­te­ri­als and the in­ter­ac­tion of ma­te­ri­als with the en­vi­ron­ment are pri­ma­ri­ly de­ter­mi­ned by sur­face con­di­ti­ons. By using plas­ma tech­no­lo­gy it is possible to spe­ci­fi­cal­ly mo­di­fy al­most any sur­face pro­per­ty and to generate new ma­te­ri­als with spe­cial func­tions that way. The ana­ly­sis of sur­faces is one of the spe­cial fiel­ds of the INP. The exis­ting spec­trum of equip­ments, the know­ledge for ope­ra­ti­on and the me­thods for analysing mea­su­re­ment da­ta are con­ti­nuous­ly ex­ten­ded and im­pro­ved. Thus, it has be­en pos­si­ble for INP to pro­du­ce high­ly pre­cise re­sults all the ti­mes and to po­si­ti­on its­elf in the world-wi­de top-le­vel re­se­arch for ye­ars. The pro­duc­tion of pre­cise re­sults and the po­si­tio­n­ing in the in­ter­na­tio­nal top-le­vel re­se­arch are gui­ding prin­ci­ples of the in­sti­tu­te.

Determination of the chemical composition and bindings in the surface

• High-resolution X-ray photoelectron spectroscopy (XPS)
  • Lateral resolution >27 µm
  • Energy resolution: 1 eV
  • 2D imaging mode
  • Ion source (argon or coronene C24H12) for the cleaning of the surface and production of depth profiles
• FT infrared spectroscopy
  • Qualitative chemical analysis of functional groups in MIR spectral range
  • Sample specific configurations: ATR, IRRAS, transmission
  • FTIR mapping of planar samples (ATR microscopy)

Determination of the morphology of the surface

• Atomic force microscopy (AFM)
  • Scan range:
    • max. 100 µm x 100 µm for overview images
    • ≤ 10 µm x 10 µm for detailed images
    • ≤ 1 µm x 1 µm for high-resolution images
  • Different measurement modes:
    • C-AFM static scanning in the contact mode
    • NC-AFM oscillating scanning in non-contact mode
    • IC-AFM oscillating scanning in approximated mode
    • LFM scanning considering lateral forces (friction measurement)
    • Maximum measurable heigth difference: 6 µm
• Profilometry
  • Height resolution: 6.5 µm, 65 µm, 131 µm, 2 mm
  • Maximum sample size: 165 mm x 165 mm x 45 mm
    Maximum lateral resolution: 4 nm
• Optical microscope with 3D function
  • Reflected light and transmitted light microscopy
  • Resolutions: 25x, 50x, 200x, 500x
  • Stereoscopic images (3D)
    Including digital image recording, video recording

Determination of the transmission/reflection of the surface

• UV-Vis spectral photometry
  • Wavelength range: 200 nm to 1000 nm
  • Optical constants (refraction index, extinction coefficient) and geometric layer thickness of single layers
  • Estimation of the band gap of semiconducting materials

Determination of the adhesive strength of the coating

• Taber test
  • Characterization of the scratch and abrasion resistance of planar samples
• Calotest (calotte grinding)
  • Layer thickness measurement from 200 nm
  • Diagnostics of multilayer structures
  • Characterization of the abrasion parameters of the coatings
• Ultrasonic bath
  • Frequency: 35 kHz
  • Power: 2 x 35 W
  • Different test liquids

Determination of the contact angle/surface energy

• Contact angle measuring instruments
  • Minimum drop volume: 0.5 µl
  • Testing with up to 4 liquids
    • Water
    • Ethylene glycol
    • Diiodomethane
    • Optional 4th liquid
  • Including video function