Solvent-assisted reduction in the lateral leakage current in solution-processed organic transistors

We report an effective method for bringing about a significant reduction in the lateral leakage current passing through the non-channel region of an organic semiconductor through an organic solvent vapor treatment. The hydroxyl-containing dimethyl-sulfoxide molecules interrupt the bulk charge transport after undergoing solvent vapor treatment and reduce the lateral leakage current effectively, but the channel current in the solution-processed organic thin-film transistors is not degraded. The lateral leakage current was found to be 20 times lower compared with the case of the non-treated device. A highly improved on/off current ratio was achieved by reducing the lateral leakage current through a solvent vapor treatment.