Experimental Relation between Stranski-Krastanov Growth of DIP/F16CoPC Heterostructures and the Reconstruction of the Organic Interface

By a combined AFM/X-ray study, we unveil a reconstruction at the organic interface accompanying the Stranski-Kranstanov growth of di-indenoperylene (DIP) deposited on fluorinated cobalt-phthalocyanines (F16CoPc). This reconstruction involves an abrupt change in the F16CoPc packing in those areas covered by DIP. After the total completion of the first DIP monolayer, the entire F16CoPc interfacial layer is reconstructed and eventually becomes buried under the growing DIP film. We demonstrate that the morphological transition from smooth to highly textured heterostructures occurring at a threshold temperature of 70 degrees C is intimately related to the thermal activation of the reconstruction of the underlying F16CoPc layers. This study provides further understanding of the molecular-scale processes that ultimately determine the controlled growth of organic heterojunctions.