Gridfluorenes-Based Small Molecular As Charge Trapping Elements For Light-Assisted Organic Field-Effect Transistor Memory

In an era of information explosion,the higher performance of memory is of great significance.And as traditional inorganic semiconductor memories are reaching their physical limits,the researchers are turning their attention to the new memories.Especially one of them is light-assisted organic field-effect transistor memory,which owns numerous advantages,such as solution processability,flexibility,low power consumption,high functional integration,and can realize multi-level optical erasing and storage by adjusting specific light wavelengths.Nevertheless,at this stage,OFET memory is facing the problems of low performance and fuzzy storage mechanism.Small molecules are more suitable for structure-activity analysis because of their clear structure.Among them,Gridfluorenes-based small molecule is a kind of material that owns abundant structural features such as nano-scale pore size,wide-band structure,large steric hindrance,etc,given this,this dissertation focus on the gridfluorenes-based small molecular as charge trapping elements for light-assisted Organic Field-Effect Transistor Memory.The relevant research contents and results are as follows:(1)To explore the effect of the alkyl chain on the storage performance of OFET memory.We found that the C0-Grid without alkoxyl substitution presents a better morphology of charge trapping layer and organic semiconductor layer,which enables the memory device to obtain a larger positive window and a better charge-trapping tolerance and stability.(2)To study the effect of electron-withdrawing group on the charge storage performance and photoresponse characteristics.After we introduce the benzotriazole to construct the D-A structure,the previously separated HOMO-LUMO energy levels overlapped,which caused a decrease in storage performance.At the same time,when gradually introducing electron-withdrawing groups,the absorption spectrum of the material in the blue light region is added,which brings about an effective improvement in the photoresponse and photorecovery performance of the device.This work shows that the construction of the D-A structure is an effective means to regulate the photoelectric properties of devices.(3)Study on multilevel optoelectronic OFET memory with Gridfluorenes-based small molecule as charge trapping layer.Multilevel optoelectronic OFET memory is successfully realized by regulating different light wavelengths,light intensity,light pulse width,and the number of pulses.This multilevel optoelectronic OFET memory can be applied in photodetector and information encryption.