The current-voltage characteristics of triethylsilylethynyl anthradithiophene (TES ADT) thin-film transistors can be improved dramatically by a simple and straightforward solvent-vapor annealing process after device fabrication. Exposing the transistors to dichloroethane vapor for 2 min induces structural rearrangement and crystallization of TES ADT (see figure and cover). This procedure results in drastic increases in on currents; the saturation mobility increases by two orders of magnitude and the current-voltage hysteresis is largely eliminated.