Recent research on organic and polymeric semiconductors is directed towards highly ordered molecular structures in solid states. Through molecular design and engineering, it has been shown possible to control the molecular orientation and processing conditions of these materials as well as fine tuning their energy levels and color emissions. Thin film field-effect transistors (FETs) have been used as testing structures for evaluating the semiconducting properties of new organic semiconducting materials. Performance similar to amorphous-Si can already be realized with some organic materials. Large-scale integration of organic transistors has been demonstrated. In addition, several low cost novel non-lithographic patterning methods have been developed, which resulted in the first flexible electronic paper. The field-effect transistor device structure can also be utilized as a means to induce a great amount of charge carriers in organic thin films through the gate field. Using this type of structure, superconductivity was observed in a highly ordered conjugated polymer.