Surface potential profiling and contact resistance measurements on operating pentacene thin-film transistors by Kelvin probe force microscopy

The surface potential imaging and profiling experiments by Kelvin probe force microscopy (KFM) was used to examine the role of contacts in bottom and top contact pentacene thin-film transistors (TFT). It was shown that KFM is sensitive to subsurface potential changes in the thin TFT accumulation layer, which was confined to the monolayers at the dielectric interfaces. The maps were used to identify bottlenecks to charge transport in conjunction with drain current measurements. The results demonstrates the utility of KFM for generating potential maps of operating pentacene TFT.