Preparation And Performance Study Of Graphene Single Material Thin Film Thermocouples

Thin film thermocouples are widely used in fields such as weapons and equipment,aerospace,production and daily life due to their small size,fast response,and high accuracy.Graphene is a two-dimensional material with excellent mechanical,thermal,and electrical properties.It has extremely low resistivity and fast electron migration speed,and can be used to produce a new generation of electronic components with smaller volume and faster conductivity.With the continuous development of modern science and technology,temperature sensors with smaller area,higher accuracy,and compatibility with existing nanomanufacturing technologies are needed in some complex electronic devices and circuits to monitor temperature changes.Existing thin film thermocouples are not suitable for the above scenarios,so graphene materials compatible with nanomanufacturing technologies are selected to prepare thin film thermocouples.This article is based on the research status of thin film thermocouples and graphene thermocouples both domestically and internationally.The structural design and simulation analysis of graphene single material thin film thermocouples were carried out,and the preparation of graphene single material thin film thermocouple chips was completed using micro/nano processing technology.Finally,the morphology,static and dynamic performance of graphene single material thin film thermocouples were tested.The main research content is as follows:Firstly,based on the thin film thermocouple effect and commonly used laws,combined with the principle of graphene single material thin film thermocouples generating thermoelectric potential,the size design of thin film thermocouples is carried out,and the material selection of thin film thermocouples is discussed.The dynamic response of thin film thermocouples is simulated using finite element software to verify the feasibility of the structure.Secondly,based on micro nano processing technology,the process design,layout design and process processing of graphene single material film thermocouple were completed.The key processes involved in the process processing,including silicon nitride insulation layer and protective layer coating and graphene ultra clean transfer process,were studied.The chip manufacturing process flow,such as insulation layer and protective layer coating process,Magnetron sputtering process,graphene transfer and graphical process,was introduced in detail,Complete the preparation of graphene single material thin film thermocouple chips.Finally,morphology,static and dynamic performance tests were conducted on the prepared graphene single material thin film thermocouple.Through Raman testing and scanning electron microscopy image analysis,it was found that the graphene material in the prepared graphene single material thin film thermocouple is a single-layer graphene with good morphology.During the static testing process,it was found that the output voltage temperature curve of the prepared graphene single material thin film thermocouple had good repeatability and linearity by conducting static calibration within the temperature range of 50-300℃.The sensitivity of the thin film thermocouple was calculated to be approximately 6.89μV/℃.The dynamic performance test uses the pulse laser method to test the thin film thermocouple.Through multiple experiments,it has been proven that the average response time of the prepared thin film thermocouple is about 11.8ms,which has the characteristic of fast response and lays the foundation for the future development of graphene thermocouples.