The Improvement of Electrical Characteristic of Solution Processed Triisopropylsilyl Pentacene Organic Thin-Film Transistors Employing Hexamethyldisilazane Treatment

Abstract

The field-effect mobility of triisopropylsilyl (TIPS) pentacene organic thin-film transistors (OTFTs) is increased considerably by employing hexamethyldisilazane (HMDS) treatment on poly-4-vinylphenol (PVP) gate insulator. A simple spin coating of HMDS on PVP gate insulator of OTFTs suppressed the void formation significantly and improved structural morphology of pentacene film. The field-effect mobility of OTFT where the TIPS pentacene was spin coated was increased from 0.01 cm2V-1s-1 to 0.1 cm2V-1s-1 after HMDS treatment. The threshold voltage was decreased from -2.8V to -2.0V. We have also fabricated ink-jet printed OTFTs and investigated the effect of HMDS treatment on ink-jet printed OTFTs. The field- effect mobility of OTFT was not increased significantly by HMDS treatment while the threshold voltage of the device was reduced considerably. The threshold voltage of untreated OTFT was +11.1V while that of HMDS treated OTFT was -3.0V. Our experiment results suggest that the HMDS treatment improved the characteristics of OTFTs.