Master thesis defence by Magni Glyvradal
Many molecular electronic devices are created by sandwiching an organic film between two metal electrodes. The organic film can be deposited on the bottom electrode by spin casting, vapor deposition, solution phase self assembly or Langmuir-Blodgett (LB) transfer. The top electrode is normally metal vapor deposited. The problems with this method are whether the film survives the metal deposition or not, and how the internal film structure is after the metal deposition. Studies using X-ray reflectivity (XR), have shown that it is possible to obtain structural information about the film and the damage caused by the metal deposition after a metal film has been deposited without damaging the device.
The samples investigated consisted of a silicon substrate where a LB monolayer of cadmium arachidate Cd(C20H39O2)2 had been transferred and samples where a triple layer had been transferred. The top electrodes consisted of 100 Å thick vapor deposited Au or 50 Å and 100 Å of Ti and Al respectively. The samples were investigated using atomic force microscopy and XR before and after the top electrodes had been deposited. The XR measurements showed that in the case of Ti/Al the vapor deposited metal was stopped at the interface whereas in the case of Au penetrated deep into the monolayer.