We have shown that thin film growth of pi-conjugated materials by seeded supersonic molecular beams (SuMBE) is an effective approach to control structure and morphology. These are key features to improve control on energy and charge transport properties and hence for the realization of improved devices including optolectronic applications. Recent results on phthalocyanines, thiophene oligomers and acenes will be discussed showing that control on the precursors, in terms of energy and momentum in particular, is of paramount importance in controlling the final properties of the films including the optical response as well as interfaces. Films showing optical properties comparable to those of the corresponding single crystals and with a controlled morphology have been produced by “tuning” the initial parameters in the beam. The initial kinetic energy, easily varied in the range from a fraction of eV up to tens of eV by changing the seeding of the molecules into an inert carrier gas (i.e. He, Ar, etc.), is shown to be a key parameter. Even the defect type and density as well as the polymorphism can be controlled by this method. In a SuMBE co-deposition scheme we have developed solar cells based on phtalocyanines and fullerenes the performance of which could be optimized by controlling the SuMBE deposition parameters. An outlook of the possible developments will be discussed in view of a new generation of devices.