Infrared Radiation Modulator Based On Ionic Liquid-graphene Intercalation Material

The dynamic control of infrared(IR)radiation has always been an important direction of IR radiation research.Under the excitation of external fields such as light,heat and electricity,the IR radiation characteristic control material can realize the reversible control of the IR response band,emissivity and reflectivity through IR emissivity tuning,IR band modulation and other ways,and then realize the controllable modulation of its IR radiation characteristics.However,effective dynamic control of IR radiation is still an urgent problem in scientific research,which has universal scientific significance and extensive application value.For this reason,this thesis researched and optimized the IR radiation dynamic control method based on the ionic liquid-graphene intercalation material,and prepared the IR radiation dynamic control device.The specific research content has the following aspects:1.Transfer and characterization of grapheneUsing a saturated solution of ferric chloride,the multilayer graphene grown on a nickel substrate by chemical vapor deposition(CVD)is etched on the substrate,and then transferred to the porous Celgard film.And prepare ionic liquid-graphene intercalation materials,use X-ray diffractometer(XRD),Raman spectrometer,etc.To study the effect of ionic liquid intercalation on the graphene lattice structure,electrical properties and optical properties,and analyze the intercalation regulation of graphene the process and mechanism of physical properties.In addition,this thesis prepared an IR radiation/reflection dynamic control pattern device constructed from an ionic liquidgraphene intercalation material and an Au total reflection substrate.The device consists of 25 "pixel" units,and small units that want to change the IR characteristics are connected with small pieces of graphene(graphene has excellent electrical conductivity).2.Design and test of IR radiation dynamic control deviceThe ionic liquid is infiltrated into the porous membrane of the transferred multilayer graphene/porous Celgard membrane sample,and then attached to the gold-plated silicon substrate,and electrodes are added at both ends of the multilayer graphene and Au to obtain a multilayer Graphene/porous Celgard membrane + ionic liquid/Au sandwich structure.By adjusting the voltage across the graphene and the counter electrode Au,the ionic liquid is intercalated into the multilayer graphene.Use Fourier Transform Infrared Spectroscopy(FTIR)to test the changes in the surface reflectivity of the ionic liquidgraphene intercalation material under different intercalation states,and study the influence of the ionic liquid intercalation on the graphene Fermi surface,carrier concentration,and intra-band and inter-band transitions of electrons.The IR thermal imager is used to detect the IR thermal image of the IR radiation dynamic control device based on the ionic liquid-graphene intercalation material,analyze the change of its surface temperature with the intercalation state of the ionic liquid,and analyze the ionic liquidgraphene intercalation by calculation.The relationship between the reflectance and emissivity of the surface of the layer material and the voltage,and further analyze the response time and repeatability of the dynamic control of the IR radiation characteristics.In addition,the design of the pattern sample has realized the adaptability of the pattern,and the transfer of graphene and the device preparation process have been optimized and strengthened.3.Design and test of IR reflection dynamic control deviceThe research is based on the IR reflection characteristics of the ionic liquid-graphene intercalation material.The prepared graphene intercalation material sample is combined with a black body radiation source to construct an IR reflection system.The IR thermal imager is used to detect the IR thermal image of the IR reflection dynamic adjustable device based on the ionic liquid-graphene intercalation material,analyze the change of its reflection temperature with the state of the ionic liquid intercalation,and analyze the ionic liquid-graphite through calculation The relationship between the reflectivity of the surface of the olefin intercalation material and the voltage,and then further analyze the dynamic control response time and repeatability of the IR reflective sample.At the same time,the pattern sample is irradiated by the black body radiation source,and the IR thermal imager is used to detect the change of the surface reflection temperature of the pattern sample with the voltage.