Microscopic Evidence for Spatially Inhomogeneous Charge Trapping in Pentacene


  • The authors thank Dr. Ricardo Ruiz and Prof. George Malliaras of Cornell University for assistance with pentacene deposition and for many useful discussions. This work was supported by Cornell University, the National Science Foundation (via CAREER award DMR-0134956, the Cornell Nanoscale Science and Technology Facility, and the Cornell Center for Nanoscale Systems, and the Cornell Center for Materials Research).


original image

Charge traps in pentacene thin-film transistors (Figure, left) have been imaged using electric force microscopy. The Figure shows a map of the trap distribution just below (middle) and well above (right) the transistor threshold voltage. It is found that the long-lived charge traps in polycrystalline pentacene are distributed inhomogeneously and do not appear to be associated with grain boundaries, as is generally assumed (see cover).