The Study On Flexible Infrared Absorbing Material And The Property Of Thermal Radiation

Infrared absorbing materials are widely used in infrared thermal imaging,infrared detection and infrared cooling.With the progress of micro-processing technology,the infrared absorbing materials are developing towards the flexible direction.Traditional flexible infrared absorbing materials have complex preparation process.A flexible infrared absorbing structure based on magnetic resonant absorption theory was proposed,and the effect of the geometrical parameters was studied by CST Microwave Studio simulation;the thermal radiation influence including single selective radiation surface,surface to surface radiation and radiation in medium was studied based on thermal radiation theory.The major work of this dissertation is as follows:(1)The structure parameters was designed based on the magnetic resonance and equivalent circuit,the absorption effect of the geometrical parameters was studied by CST microwave studio simulation.The results reveal that when the unit cell length was 4?m,the absorption peak was 9?m.The absorption wavelength was increased with the cell length increased;the absorption effect was increased first and then decreased with the top metal thickness increased;the absorption wavelength was decreased and absorption effect was increased first and the decreased with the dielectric layer thickness increased.After software optimization,the unit cell length was 4?m,the period length was 10?m,the top metal layer thickness was 100 nm,the dielectric layer thickness was 200 nm,and the bottom metal layer thickness was 1.2?m;(2)The technological parameter was studied during the fabrication of flexible infrared absorbing materials: the lithographic process parameters was studied to make the photoresist cross section became inverted trapezoidal.Such as the spin-on PR coating speed was 3000pr/s;the reverse baking time was 125s;the generic exposure time was 60s;the developing time was 24 s.The coating process was studied to achieving a good film.The coating rate was fast for the metal thin film and slower for the oxide thin film;(3)The two models of infrared thermal radiation was studied based on the theory of infrared thermal radiation and software simulation.The results reveal: the model of single selective radiation surface was made to analysis the impact of surface radiation characteristics,when the selective radiation surface's center wavelength of high emissivity window was 6?m and the bandwidth of high emissivity window was 1.7?m,the selective radiation surface temperature was 24.7K lower than the low emissivity surface under the bottom temperature was 700 K.The model of surface to surface heat radiation was made to analysis the impact of surface radiation characteristics and ambient temperature.The heat radiation in medium was discussed to find out the impact of air infrared transmission.