Lifetime enhancement of organic thin-film transistors protectedwith organic layer

We investigated the long-term performance of pentacene organic thin-film transistors (OTFTs) passivated with a 200 nm thick tetratetracontane ( n - C 44 H 90 ) . The mobility of the passivated OTFTs in 50 days was 0.143 cm 2 ∕ V s , which was almost the same as that ( 0.12 cm 2 ∕ V s ) of OTFTs before passivation process. The performance of unpassivated OTFTs exponentially degraded and almost failed in 5 days of exposure to an ambient condition. From the time dependence study for the performance of OTFTs, we found that the performance degradation mechanism of the two OTFTs is different and moisture is a more dominant factor for the performance degradation of the OTFTs.