TUD

Controllable doping of organic semiconductors is of paramount importance for future application of organic electronics; however, effective air-stable and solution-processable n-type dopants are still rare. A new class of molecular materials based on 1H-benzoimidazole derivates has recently been identified as promising candidate for strong n-type doping. Whereas the experimental results look encouraging, there is still a lack of knowledge on the detailed doping mechanism. Therefore, we have investigated the properties of one particular dopant on a single molecular level by scanning tunneling microscopy (STM) at low temperatures. By depositing dopant and C60 molecules on the same Au(111) surface, the electronic and structural interactions of the host-guest system can be addressed. In particular, spectroscopic measurements of dopant molecules resting on C60 clusters will help to understand the working mechanism of the doping effect.