Point contact current-voltage measurements on individual organic semiconductor grains by conducting probe atomic force microscopy

Conducting probe atomic force microscopy was demonstrated to provide reproducible point-contact measurements of the current-voltage characteristics of single grains of the organic semiconductors. Au-coated AFM probes were used to identify individual sexithiophene grains ranging from 1 to 6 molecules in thickness. Analysis of the measured current-voltage curves allows estimation of the grain resistivity, carrier density, contact resistance, and the effective barrier height.