Study Of Indium-tungsten-oxide-based Electric-double-layer Thin-film Transistors And Their Artificial Synaptic Devices Application

At present,oxide thin film transistors have attracted wide attention because of their advantages such as high mobility,high light transmittance,high current switching ratio,and low operating voltage.The most commonly used oxide material is amorphous indium gallium zinc oxide(a-IGZO)which has good light transmittance and electrical conductivity.However,Ga2O3 and Zn O in a-IGZO are not acid-resistant,they are sensitive during the wet etching process,and the device lacks stability.In recent years,researchers have found that amorphous indium tungsten oxide(a-IWO)has higher bond dissociation and better acid resistance,and has the characteristics of high stability and high mobility.Therefore,IWO-based TFTs have been used in the fields of flat panel displays and sensors.In addition,a TFT device prepared by using an electrolyte having an electric double layer effect as a gate dielectric layer has a large gate capacitance,requires only a low operation voltage to drive the device,and generates lower power consumption,which is beneficial to the development of portable devices.In recent years,people have been inspired by the human brain to try to build circuits similar to human brain neural networks from the bottom.Therefore,in the field of biomimetic devices,thin film transistors can be used to simulate biological synapses to achieve synaptic functions.In this paper,electric double-layer thin film transistors with IWO as the active channel layer and chitosan electrolyte solution as the gate dielectric were successfully prepared on conductive glass substrates and flexible paper substrates.The preparation process mainly includes: firstly depositing a bottom electrode on the substrate;then spin-coating a layer ofchitosan electrolyte as a gate dielectric on the bottom electrode;then depositing an IWO channel layer by a magnetron sputtering method;An Ag thin film is deposited as a source-drain electrode by evaporation.Use a semiconductor parameter analyzer to test the electrical performance of the device.The test results are as follows: IWO-based electric double-layer thin-film transistors on glass substrates have good electrical performance,the threshold voltage of the device is 0.6V,the current switching ratio is5*107,the field-effect mobility is 18 cm2 V-1s-1,The threshold swing is111 m V/decade.We tested the transmission characteristic curve of IWO-TFT as an inverter,and confirmed that the device has a good switching ability;IWO-based TFT devices with flexible paper as the substrate have good electrical performance,and the threshold voltage is0.2V and the current The switching ratio is 1.3*106,the field-effect mobility is 15 cm2 V-1s-1,and the subthreshold swings are 117 m V/ decade,respectively.We also implemented inverters,NAND gates,and Schmitt triggers using flexible IWO-TFT.In addition,since the ion-related electric double layer modulation principle of electric double layer TFT is similar to the signal transmission process of synapses,we also use IWO-TFT as a neuromorphic transistor to achieve its bionic function.In summary,the low-voltage IWO-based electric double-layer thin film transistors we prepared at room temperature have application value in the fields of flexible electronics,synaptic bionic devices,integrated circuits,and sensors.