The Effect Of Electrolyte-gated Ions Migration On The Accumulation Organic Electrochemical Transistor Performance

Organic electrochemical transistors（OECTs）are characterized by a low operating voltage,a simple preparation process,and the ability to function in solution.They hold significant promise across a broad spectrum of applications,including chemical and biological signal sensing,neuronal simulation,and printed electronics.Ion migration plays a crucial role in device performance by governing the electrochemical doping of channel materials via gate voltage.In this thesis,the effect of ion migration on device performance is investigated through the selection of different electrolyte materials,with the aim of proposing research strategies for elucidating the underlying mechanisms and optimizing the performance of such devices.The main research contents are outlined as follows:（1）The aqueous solution electrolyte-gated accumulation OECTs are fabricated using alkali metal chloride salts and alkali metal perchlorate salts.The study reveals the influence of anion and cation migration from the aqueous solution on device performance.In chloride salt devices,surface doping is observed,resulting in smaller on/off ratios,transconductance,and mobility,coupled with weak hysteresis characteristics.Notably,cations exhibit no obvious effect on the hysteresis characteristics.In contrast,perchlorate devices demonstrate bulk doping,yielding larger on/off ratios,transconductance,and mobility,along with pronounced hysteresis.The severity of hysteresis increases with the cation’s radius.（2）The effects of different ions and concentrations on device performance in PEO solid electrolyte-gated accumulation OECTs are investigated.The study identifies the influence of salt concentration in Cs Cl O₄ devices,where low concentration restricts ion doping,and high concentration limits ion dissociation.Furthermore,the influence of cations on the performance of PEO:perchlorate electrolyte-gated OECTs is explored,revealing that reduced cation radius results in increased on/off ratio,transconductance,mobility,and lower threshold voltage.In addition,attempts to create electrochemical light-emitting transistors show that devices based on Cs Cl O₄ exhibit the best light-emitting characteristic among PEO electrolyte-gated devices.（3）The development of accumulation organic electrochemical transistors using perovskite(PEA₂MA_n-1Pb_nBr_3n+1,Cs Pb Br₃)as the electrolyte is explored.The utilization of the PEO layer is found to reduce the gate leakage current and provide ion migration channels,enabling gate regulation of the device.Furthermore,electroluminescence is achieved in perovskite electrolyte-gated OECTs,leading to an exploration of the regulation and influence mechanism of ultraviolet light on the current in perovskite electrolyte-gated devices.