Pentacene Organic Thin-film Transistors Based On The Elastic Gate Dielectric

Pentacene thin-film transistors have been widely studied over the past ten years due to the advantages of high mobility,large area preparation,and flexible substrate compatibility,etc.They have the potential applications in low cost,large area,flexible electronics.To effectively improve the flexibility,the inorganic dielectrics are replaced by the polymer dielectrics.Polydimethylsiloxane(PDMS)is the most widely used silicon-based orgainc polymer.Its outstanding properties such as bicompatibility,optical transparency,flexibility,excellent elasticity and good dielectric properties,have provided big opportunities for a wide variety of applications as flexible substrate and stamp.However,the direct deposition of organic thin film on PDMS for organic thin-film transistors is challenging.In this paper,organic semiconductor thin film have been deposited on PDMS after suface treatment.Meanwhile,three new device configurations are designed for flexible organic thin-film transisitors.The main works are as follows:1.In order to improve the performance of the thin-film transistors,the deposition temperature and purification process were analyzed.The results showed when the deposition temperature is 50 ?,the device mobility is the highest.Meanwhile the purification process is very important for the preparation of pentacene thin-film.We also confirmed the instability of the pentacene thin film in air.2.The elastic gate dielectric of the device is PDMS.We designed a novel anhydrous surface modification method and optimized the oxygen plasma treatment time and gas phase OTS modification time with several devices in the same conditions.The experiment results indicated that the transistors showed the highest carrier mobility at 0.65 cm2V-1s-1 when the oxygen plasma treatment time was 100 s at 50 W and OTS vapor deposition time was 7 h at a temperature of 120?.3.Fexible pentacene thin-film transistors with elastic gate dielectric have been fabricated for three different configurations.Moreover,they have a certain bending capacity by testing the performance of the device after bending.Conformal pentacene thin-film transistors have been constructed,which can be attached to a three-dimensional substrate.Our study opens up the capability of PDMS for flexible and conformal devices and reveals the strong potential for future large-scale wearable and implantable electronics.