Morphology and conductivity modification of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) films induced by conductive atomic force microscopy measurements

Morphology and conductivity modifications in poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films induced by conductive atomic force microscopy probe are investigated. At an applied bias of positive or negative 10 V, raised features of 12.8±1.8 nm in height are generated and the local film conductivity is reduced. The feature height formation is irreversible and dependent on both applied bias and tip velocity. The mechanism by which these features are generated is proposed to be mass transport of PSS− to the surface under the atomic force microscope tip. This finding may open up the possibility of patterning PEDOT:PSS films, and thereby organic optoelectronic devices.