Polymer thin-film transistors based on poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) have been fabricated by spin-coating process and characterized. The electrical characteristics of the devices stored in dry air show obvious degradation with a smaller mobility due to oxygen effect, and lower threshold voltage. The devices present good optical response in low-light condition and optically induced memory effects, demonstrating their use as promising smart light-detection devices. Moreover, solution preparation, deposition and device measurements have been all performed in the air for the purpose of large-area applications. (c) 2006 Elsevier B.V. All rights reserved.