Surface roughening evolution in pentacene thin film growth

Abstract

We report investigation on the surface roughening evolution during the pentacene thin film growth, and it turns out to be the overall hopping-up mass transport from the under layers to the upper layers responsible for the surface roughening. A simple interlayer mass transport model utilizing a roughness evolution ratio has been developed, based on which the extent of the interlayer mass transport is found to be reduced with the film thickness. The surface roughening mechanism is considered to be associated with the gradual phase change with the film thickness due to the pentacene polymorphism.