Scanning Tunneling Microscopy

picture of STM STM picture


We have several homebuilt STMs for ambient conditions and a combined STM/AFM working under UHV.


principle of scanning tunneling microscope

prinziple of STM

Principle of STM
(to see a more detailed graphic click here)


I ~ U * k/s * exp(-2ks)


I := tunneling current
U := tunneling voltage
1/k := range of wavefunction out of solid
s := distance tip-sample


The STM makes an image of the local electron density of states containing:

- topographic information
- spectroscopic information