Research On The Preparation And Performance Of Organic Thin Film Transistors Based On Carbazole Polymers

Organic thin film transistors（OTFTs）are increasingly favored for their low cost,simple preparation process,large-area fabrication,and fabrication on flexible substrates.In recent years,OTFT has developed rapidly and has great application potential in the fields of flat panel displays,detectors and sensors.However,OTFT still has problems such as low crystallinity of organic semiconductors,high threshold voltage and poor device stability.In this paper,a novel polymer semiconductor material was synthesized from carbazole,and the performance of thin film transistor based on the semiconductor material was studied,the main contents are as follows:The polymer PBCB-HH-DF was synthesized by Suzuki coupling reaction,and the thermal properties,photophysical properties,electrochemical properties of the synthesized polymer were analyzed by thermogravimetric analyzer,ultraviolet analyzer and electrochemical workstation.The polymer showed good performance for thermal stability and lower highest occupied molecular orbital.A thin film transistor based on PBCB-HH-DF was fabricated,the effects of insulating layer material,insulating layer thickness,active layer annealing temperature,and the annealing time on transistor performance were investigated.The performance of the transistor was investigated under different conditions,Polymethylmethacrylate is used as the insulating layer with a thickness of 847 nm,when PBCB-HH-DF is annealed at 150°C for 30 min,the transistor performance is optimal,the carrier mobility is 1.67×10^-2 cm²/Vs,the threshold voltage is-4.8 V and the switching ratio can reach 1.2×10⁴.The devices showed good performance,indicating that carbazole polymers have certainly research significance in the field of OTFT.