A nanogroove-guided slot-die coating technique has been developed to manipulate the alignment of polymer chains within a short processing time. A combination of directional movement of slot-die and uniaxial nanogrooves on the substrate for the unidirectional flow of solution suppresses the multiple degrees of conformational freedom, resulting in long-range oriented polymer films and a high field effect mobility of ∼5 cm(2) V(-1) s(-1).