Performance enhancement in mechanically stable flexible organic-field effect transistors with TIPS-pentacene:polymer blend

Abstract

Flexible organic field-effect transistors (OFETs) with TIPS-pentacene: polystyrene (PS) blend are demonstrated to exhibit enhanced mobility and significantly improved electrical stability compared to neat TIPS-pentacene on poly(4-vinylphenol) (PVP) dielectric (bi-layer OFETs), along with high mechanical stability. Due to merit of high quality dielectric-semiconductor interface, pristine TIPS-pentacene: PS blend OFETs exhibited maximum mobility of 0.93 cm2 V−1 s−1 with average of 0.44(±0.25) cm2 V−1 s−1 compared to 0.14(±0.10) cm2 V−1 s−1 for bi-layer OFETs with high current on-off ratios on the order 105 for both. Both types of devices exhibited high electrical stability upon bending with increasing magnitude of strain or its duration up to 5 days. However, significant differences in electrical stability of devices were observed upon applying constant bias-stress for 40 min to 1 h. Pristine blend devices exhibited outstanding electrical stability with very low drain current decay of <5% compared to ∼30% for bi-layer devices. Even upon bias-stress after 5 days of bending, the drain current decay levels were only changed to <10% and ∼50% for blend and bi-layer devices respectively.