Devices Stability Analysis Via Polyimide Gate Dielectric Interface Study In Organic Thin Film Transistors

The grand vision of next generation electronics is expected to realize via the wholescale industrialization of organic devices.However,several serious obstacle hindering the practical application for organic devices is their relatively low mobility and instability.Based on extensive research,gate dielectric layer plays an important role in organic thin film transistors?OTFTs?due to its influence on mobility,power consumption and stability of the device.Despite unilateral progress has been made by materials design and interface engineering,the flawed dielectric is still unable to achieve comprehensive excellent performance for practical application.Herein,fluorinated dielectric material were designed for performance improvement and stability enhancing.Devices with both good heat-resistant and high electrical stability were also realized.TFTs with fluorinated polyimide?ODA-6FDA PI?and silicon dioxide?SiO2?bilayer as gate dielectric,exhibit superior electrical stability under protracted gate bias-stress for 150 min(?V_th¹V with voltage range 30^-60 V)and extremely less susceptible to annealing treatment for temperature up to 150°C???/?0².9%?,as compared to counterparts with single dielectric layer.In addition,we also studied the effect of different fluorine content of PI on the photo response of TFT devices,and found that with the increase of fluorine atom content,the sensitivity of the device to light is reduced,indicating that FPI can improve the light stability of the device.Further,the underlying mechanism of fluorinated dielectric is investigated.The hydrophobicity of the upper layer of fluorine-containing polyimide to reduce the probability of charge trapping by traps,while the fluorine-containing polyimide as an organic polymer has a thermal expansion coefficient that matches the organic semiconductor layer and a good ductility,thereby increasing the transistor.The thermal stability of SiO2 is mainly to reduce the back channel effect caused by the high permanent dipole moment of the fluorine-containing group in the fluorine-containing polyimide,reduce the dark current of the device,increase the switching ratio,and suppress the positive of the threshold voltage.Drifting.The strong hydrophobicity and low surface energy of FPI can effectively reduce the light adsorption of water and oxygen in the air and the defect state density of the interface,which can greatly reduce the photo response of the TFT device.These researches present that gate dielectric plays a vital role in devices performance and we firmly believe that the concept of applying fluorinated dielectrics provides a consistent picture of ambitious exhibition for OTFTs.