Oxide Neuromorphic Transistors And Logic Circuit Applications

Synaptic activity plays an important role in brain nerve activity.The power consumption of a single synaptic event is extremely small,which makes the brain very efficient in information processing and storage.The traditional von Neumann architecture center often requires complex algorithms when running,and the power consumption is extremely high.Therefore,designing neuromorphic systems is of great significance for efficient information processing.There have been reports of complementary metal-oxide-semiconductor neuromorphic circuits,but the power consumption of the circuit is much higher than that of biological synapses.Therefore,to develop solid-state neuromorphic devices with ultra-low power consumption and to simulate synapse function have potential significance for realizing an efficient neuromorphic platform.An electric double layer transistor is a type of field effect transistor using an electrolyte as a gate medium.Under the gate voltage,the ions in the electrolyte migrate,and the working mode of the transistor is regulated,which provides the possibility of obtaining low-voltage transistors and achieving low power consumption of devices.This thesis focuses on oxide thin-film transistors.On the one hand,an oxide thin-film transistor with a multi-gate structure was prepared,and several types of logic circuits were designed to implement multi-logic function applications.On the other hand,an oxide thin-film transistor with a bottom-gate structure was prepared.By adjusting the operation mode of the transistor,ultra-low power consumption of the transistor was achieved.The main contents are summarized as follows:?1?Preparation of solid electrolyte film and its electrical properties.PVA electrolyte film and PVA/GO hybrid electrolyte film were prepared by solution method,respectively.The obtained films were tested for different properties.When the bias voltage scan from-1.5 V to1.5 V,the PVA electrolyte film has a leakage current lower than¹0 nA,and the PVA/GO hybrid electrolyte film has lower⁵ nA leakage current.In addition,both films have huge EDL capacitances greater than 1?F/cm².The above characteristics indicate that both solid electrolyte films have good electrical properties.?2?Fabrication and performance characterization of oxide neuromorphic transistors.Based on the above two kinds of electrolyte films,bottom-gate and in-plane-gate oxide neuromorphic transistors were prepared,and the electrical properties of transistors were tested.The oxide thin-film transistor based on PVA solid electrolyte has a current on/off ratio as high as⁵.6×10⁶,a subthreshold slope of¹34 mV/Dec,and a carrier mobility of¹.2 cm²V^-1s^-1.In addition,such transistors are soluble in water.The oxide neuromorphic transistor based on PVA/GO hybrid electrolyte has a carrier mobility of⁶.6 cm²V^-1s^-1.?3?Realize multiple logic function application of oxide thin-film transistor.Three different logic circuits were built using PVA/GO hybrid electrolyte-based oxide thin-film transistors including"NOT","AND",and"NAND".They have uniform high and low potentials,that is,2 V and-2 V are defined as logic states"1"and"0",respectively.In these logic circuits,a transistor/resistor structure is used.?4?Realize biological synaptic function application of oxide thin-film transistor with ultra-low power consumption.A PVA electrolyte-based indium tin oxide?ITO?thin-film transistor with low operating voltage was prepared.By adjusting the channel thickness of the transistor,its influence on synaptic performance was studied.Basic synaptic functions are simulated in the proposed oxide neuromorphic transistor,including excitatory postsynaptic current?EPSC?,paired-pulse facilitation?PPF?,enhancement/inhibition properties and the multistore model of human memory.In addition,when the device is operating in deep enhancement mode,the neuromorphic device possesses ultra-low power consumption and ultra-high sensitivity.The effectiveness of EPSC is further validated by the PPF effect.Therefore,due to the excellent electrical characteristics and low power synaptic response,the oxide thin-film transistor proposed in this paper has potential application value in ultra-sensitive neuromorphic systems,efficient electronic biological interfaces,and portable electronics.