Abstract：

In the past decade, significant progress has been made in the fabrication of organic optoelectronic devices, such as organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) or organic photovoltaics (OPVs), predominantly due to important improvements of existing materials and the creation of a wealth of novel compounds. Many challenges, however, still exist. In the field of OPVs, real understanding of what structural and electronic features determine, for instance, the short-circuit current (J_sc), open-circuit voltage (V_oc) and fill factor are still lacking; and the role of charge transfer states and which charge transfer states are critical for efficient charge generation is still heavily debated. Here we attempt to obtain further insight of relevant structure/ processing/ performance interrelations using classical polymer processing ‘tools’. We present a survey on the principles of structure development from the liquid phase of this material family with focus on how to manipulate their phase transformations and solid-state order to tailor and tune the final ‘morphology’ towards technological and practical applications, and establish correlations with relevant device characteristics. This will include the interrelation of intermixed phase with charge transfer absorption, how we can manipulate the charge transfer energy and what structural features seem to influence V_oc. Similar aspects in the OFET field will also be addressed.