Novel Organic Semiconductor Materials For Photoresponsive And Optical Information Storage Transistors

Organic semiconductor because of the combination of desirable properties such as low-temperature processing,large-area fabrication,mechanical flexibility,and readily tunable molecular structures and performance.Therefore,this field has been nourished by tremendous efforts,resulting in broad potential applications such as optical communications,imaging systems,night vision,and medical diagnoses.however,because of the nonpositive correlation relationship between the photo/dark current ratio(P)and the gate voltage,the claimed best P,R(photoresponsivity),and D*(detectivity)can hardly be obtained simultaneously at a given gate voltage,which severely compromises the device performance.we develop a light and voltage dually gated transistor based on the organic semiconducting single crystal of DTAnt.This work reforms the interdependency of gate voltage and P,enables the possibility to facilely regulate device performances,and opens new directions in phototransistor design.we synthesize a novel A-?-D-?-A-type organic semiconductor named as IDTOT-4F.More importantly,IDTOT-4F based optoelectrical devices exhibit good optical memory characteristics.The specific contents are as follows:Here,a light and voltage-dually gated transistor based on organic semiconducting single-crystal of 2,6-dithienylanthracene(DTAnt)is developed.Experimental results show that the switch ratio is very low in the dark,but the mobility can be significantly increased in the light condition;this phototransistor shows good performance with P of 3.83×10~3,R of 1.32 A W^-1,and D*of 1.94×10¹² Jones achieved simultaneously at V_g=-100 V.Besides,the good reversibility and repeatability of its light-responsive behavior allows for constructing artificial photonic neuromorphic device with demonstrated synaptic functions,including excitatory postsynaptic current(EPSC),short/long-term memory(STM/LTM)and pair-pulse facilitation/depression(PPF/PPD).A novel photoactive semiconductor(named as IDTOT-4F)with an A-?-D-?-A-type configuration is synthesized.It contains an electron-donating fused ring(D)as the core flanked with two?-spacers and is end-capped with two electron-withdrawing units(A).This unique molecular configuration gives it a strong internal charge transfer effect,which makes it have a strong and wide light absorption band and a relatively narrow band gap(1.46 e V).Thin-film optoelectrical devices based on IDTOT-4F exhibit both n-type and p-type switching behaviors.In addition,the p-channel device shows superior photosensitive performance with a P_max value of about 60,R_max of 0.07 AW^-1,and D_max*of 2.5×10¹⁰ Jones.Further,IDTOT-4F based optoelectrical devices show good optical memory characteristics and the time constant?₁ is 4.6h,which indicates that it is suitable for nonvolatile optical storage devices.The results provide new perspectives into the photoresponsive behavior of fused-ring semiconductors and offer a new way for the design of nonvolatile optical memory devices.