Research On Organic Thin Film Transistors And Ferroelectric Organic Transistor Memories Based On The Composite Gate Dielectric Layer

The information industry occupies an important position in the national economy;All kinds of new electronic products promote the advancement of technology,and also make people's life and work more convenient.As one of the basic components of electronic products,transistors play an important role in the information industry.In recent years,organic thin film transistors(OTFTs)based on organic semiconductors have been widely used in flat panel displays,flexible integrated circuits,sensors,memory and other fields with their advantages of low price,solution processing,low temperature preparation,and good mechanical flexibility.Its application prospects have attracted lots of attention of researchers.Device performance is one of the main problems to limit the development of OTFTs and their functional applications.The gate insulating layer has important influence on the performance of OTFTs and their functional applications.We have made much systematic work on the gate insulating layer to improve the comprehensive performance parameters of OTFT.At the same time,we also have developed the functional application of OTFT in non-volatile memory(NVM).(1)We designed and prepared a high-performance flexible OTFT with a composite gate insulating layer based on the three-layer polymer film and achieved the goals of reducing the operating voltage of the device,improving the field effect mobility and working stability.And we analyzed the physical mechanism of improving the comprehensive performance parameters of flexible OTFT based on the structure of the composite gate insulating layer systematically.As a result,the operating voltage of flexible OTFT can be as low as 4 V,the field effect mobility is as high as 2.6 cm2/Vs,and it also exhibits good working stability and mechanical flexibility.(2)We developed the functional application of OTFT in memory.Based on the all-solution process,a transparent ferroelectric organic thin-film transistor non-volatile memory(Fe-OTFT-NVM)with good optical stability was designed and prepared.The field-effect mobility reached 0.73 cm2/Vs.Simultaneously under the erasing and writing voltage of±70V,the storage switching ratio reaches 10~3?10~4,the storage window reaches about 50V,and the storage holding time is50000s.Under the light with wavelengths of 490,565,and 625 nm,the transparency of Fe-OTFT-NVM reaches more than 80%,and exhibits good photostability.(3)At present,the high operating voltage is still a common problem in Fe-OTFT-NVM,and it is also one of the main problems to limit its practical application.To this end,we designed and prepared a Fe-OTFT-NVM with a composite gate dielectric layer structure with P(VDF-TrFE)as the insulating layer and cross-linked PVP as the modification layer.The working voltage of the device reaches±4V,and the storage performance of the device is very stable during the holding time of 8000s,and the number of reliable erasing and writing cycles exceeds 1000 times.