Bilayer-passivated stable dif-TES-ADT organic thin-film transistors

The active region of organic thin film transistors (OTFTs) is usually sensitive to moisture and O-2 in the air ambient, which hinders their practical applications. In this study, the effects of air ambient on characteristics of unpassivated 2,8-difluoro-5,11-bis (triethylsilylethynyl) anthradithiophene (dif-TES-ADT) OTFTs are clarified. The device is much more sensitive to H2O vapor than O-2, although both of which cause TFT instability. To improve the environmental stability, inkjet-printed passivation of the fluoropolymer CYTOP and UV curing adhesive are compared. It is found that the CYTOP passivation is well compatible with the organic channel while the UV curing adhesive has excellent barrier ability to both H2O vapor and O-2. Then CYTOP/UV adhesive bilayer passivation combining advantages of both materials is introduced to achieve stable operation of OTFTs, which can resist saturated H2O vapor and O-2 for 25 days.

Automated summary

The study found that organic thin film transistors are more sensitive to moisture vapor, but both moisture vapor and O-2 can cause instability in the transistors. By comparing the effects of different sealing materials, it was discovered that the CYTOP/UV adhesive bilayer passivation combines the advantages of both materials, enabling OTFTs to resist saturated moisture vapor and oxygen for 25 days.