SPM / Key capabilities

  • Multimode scanning probe microscopy & optical microscopy for operation in air or liquid
  • Cryogenic scanning tunneling microscopy
  • Cryogenic atomic force microscopy
  • Variable temperature electrostatic force miscroscopy & Kelvin probe microscopy
  • Surface analysis tools combined with scanning tunneling microscopy
  • 4-point Nanoprobe microscopy with electron microscopy and ultrafast optical spectroscopy

This project combines both SPM and ultrafast laser spectroscopy to study the dynamics of electronic phenomena in nanostructures as well as in nanodevices under operation, at the atomic scale, with time-resolved tunneling current extending from subpicosecond to the ms range. Two ultra high vacuum systems are coupled with the same optical pump-probe setup: a multiple probe scanning tunnelling microscope where the unique combination of four STM probe tips and a scanning electron microscope (SEM) in ultra high vacuum allows 4-point contact measurements and function testing of nanodevices within complex structures and a low temperature atomic force microscope. The optical pump-probe technique allows to illuminate a sample with a sequence of paired laser pulses separated by a variable delay time. From the electro-optical modulation of the delay time, the change of the tunneling current intensity reflects the spatial excitation and relaxation of the photo carriers in the sample with a time resolution corresponding to the pulse resolution (~140 fs).