Interrupted Growth to Manipulate Phase Separation in DIP:C60 Organic Semiconductor Blends

We studied the influence of periodic growth interruptions during codeposition of diindenoperylene (DIP) and buckminsterfullerene (C60) in an equimolar mixing ratio. DIP and C60 are known to phase-separate when codeposited, but the details and, in particular, the length scales depend on kinetic factors. Using X-ray scattering and atomic force microscopy, we demonstrate that the phase separation mechanism is in fact influenced by growth interruptions, with more pronounced effects if the deposition rates are low. For high deposition rates, growth interruptions have no appreciable effect. We discuss our proof-of-concept investigation in the context of the relevant processes and their time scales.