Here, a new approach is introduced to prepare large single crystals of π‐conjugated organic molecules from solution. Utilizing the concept of azeotropism, single crystals of tri‐isopropylsilylethynyl pentacene (TIPS‐PEN) with dimensions up to millimeters are facilely self‐assembled from homogeneous solutions comprising two solvents with opposing polarities and a positive azeotropic point. At solvent compositions close to the azeotropic point, an abrupt transition of morphology from polycrystalline thin‐films to large single crystals is found. How to adjust the initial ratio of the binary solvents so that the change in solvent composition during evaporation favors the specific H‐aggregation and promotes an efficient self‐assembly of TIPS‐PEN is explained. The charge‐carrier (hole) mobilities are substantially enhanced by a factor of 4 from the morphology of thin‐films to large single crystals used as active layer in field‐effect transistors. Additionally, this approach is extended to other π–π stacked organic molecules to elucidate its broad applicability.

Monodisperse microfiltration membranes are fabricated using interference lithography. The versatility of this technique to produce polymeric membranes optimized for flow and selectivity characteristics with a wide variety of pore geometries and dimensions is demonstrated.

The rich phase behavior of 5,11-bis(triethylsilylethynyl) anthradithiophene (TES ADT) – one of the most promising, solution-processable small-molecular organic semiconductors – is analyzed, revealing the highest performing polymorph among four solid-state phases, opening pathways toward the reliable fabrication of high-performance bottom-gate/bottom-contact transistors.