CHARGE INJECTION AND EXTRACTION ON ORGANIC DOT STRUCTURES BY ATOMIC-FORCE MICROSCOPY

We describe the manipulation of the charged state of nanoscale organic ''dot'' structures using the atomic force microscope, Electric charge s were injected into single dots by contact electrification from an at omic force microscope tip to which voltage was applied. On measuring t he charge distribution two-dimensionally, it was found that the inject ed charges were stably confined in the dot structures for an extended period. The number of injected charges could be controlled down to sin gle elementary charge. Further, injected charges could be reextracted from the dots by using a tip with reduced applied voltage. However, co mplete extraction from highly charged dots was difficult, which sugges ts that some transfer of charge from dots to adjacent regions may occu r. (C) 1996 American Vacuum Society.