Low Voltage Indium-Zinc-Oxide Homojunction Thin-Film Transistors With Pea Protein Gate Dielectric

The oxide thin-film transistors,represented by IGZO and IZO,have the advantages of high mobility(>10cm2/Vs),large area fabrication at low temperature and compatibility with flexible substrates,and have an important application prospect in the fields of electronic paper,plate display,sensor,neural morphology and so on.However,due to the weak coupling of capacitance between the active channel and the gate,the open voltage and power consumption of the tradition IZO-TFT are high,which does not conform to the trend of the device energy saving and portable.under gate voltage,gate dielectric of ion conductive can form double electric layer,so it can solve the problem of weak charge coupling in traditional gate dielectric.At the same time,the increasing number of waste electronic products has attracted more and more people's attention to the problem of waste.With the increasing awareness of environmental pollution,the biodegradability,biocompatibility and biodegradable environmental friendly biomaterials have received considerable attention.Among them,degradable materials and biological materials have attracted many researchers'interest.The pea protein gate dielectric used in this paper not only has the advantages of biodegradability and biocompatibility,but also is the gate dielectric of ionic conduction.In this paper,we successfully manufactured a IZO-based thin film transistor,with pea protein as a gate dielectric on the ITO conductive glass substrate.Manufactured IZO thin film transistor is a bottom gate structure.The production process as follows:spinning 1ml 0.8%concentration of pea protein in the ITO conductive glass(the bottom gate of the device is ITO),and then drying in the oven,and then using a specific mask that can simultaneously control magnetic sputtering IZO channel and the source and drain electrodes(the channel and source,drain electrodes of the device are all IZO).The process is carried out at room temperature,and the channel length and width of TFT determined by mask are 1000?m and 80?m,respectively.We used characterizations of SEM,FTIR,and AFM to characterize the cross section,functional group and surface of the pea protein film on the silicon substrate,characterization results as follows.1)The characterization results of SEM show that the thickness of pea protein film is 8.8?m;2)The characterization results of AFM show that the RMS roughness of pea protein film is 4.375 nm;3)The characterization results of FTIR show that there are a lot of mobile ions in pea protein film.In addition,we used the semiconductor parameter analyzer Keithley 2636B to characterize the electrical properties of pea protein IZO devices.First,the capacitance of the device measured by using the two terminal structure of the bottom gate and the source electrode is 2.0 ?F/cm2 at the frequency of 1.0 Hz.Then obtained from the transfer curve,the switching ratio,the threshold voltage and the subthreshold swing of the device are 3×106,0.1 V and 167 mV/decade,respectively.Taking the required parameters into the mobility formula,the mobility can be found to be 27.6cm2/Vs.Besides,we implement the function of the inverter with the device,in which the maximum gain of our inverter reaches 18 when the gate voltage is 5V,and the function of the Schmidt trigger is realized at low frequency by the inverter receipt;Finally,we tested the stability of the device and found that the performance of the device was unchanged after multiple switches.Then the threshold voltage was tested with the aging of the time,it was found that a good aging phenomenon that the threshold voltage of the device just offset 0.4 V in four months.The above results show that our pea protein IZO TFT device has the advantages of low pressure opening,high mobility and room temperature production,so that it has broad prospects in a generation of low power,high performance,environmentally friendly electronics.