Thermal stability of organic thin-film transistors with self-assembled monolayer dielectrics

We have investigated the annealing effects on 2 V-operation pentacene organic thin-film transistors (TFTs) with self-assembled monolayer-based gate dielectrics. When pentacene TFTs without passivation layers are annealed at 100 °C, the pentacene crystal structure changes to the bulk phase, resulting in an irreversible degradation of electronic performances. This degradation is suppressed by a 2.5-μm-thick passivation layer. The mobility of the encapsulated TFTs decreases by only 12% upon annealing at 140 °C. We have also investigated the bias-stress effect and found the drain current of low-voltage pentacene TFTs annealed at 70 °C decreases by 1% during continuous bias stress for 1 h.