Application Of Stable Sputtering AlN In Vacuum Solar Collector Film Layer

In china,the solar water heaters are widely used in the field of solar thermal applications.The vaccum tube of the solar water heater,which is the main funtion component,translates the solar energy to the heat energy by selective absorption layer.When the solar energy industry produces solar collectors,AIN thin films are widely used as absorption layers and anti-reflection layers.The vacuum tube anti-reflection layer requires the AIN film to be sufficiently pure,uniform in thickness and the metal content is close to zero.Therefore,the reactive magnetron sputtering of the AIN film becomes a key technology for preparing the vacuum tube absorption film layer.In this thesis,we first reviewed the solar selective absorption surface layer,the preparation method and the current progress of the reactive sputtering AIN thin films.Then we proposed the main process parameters needed to control during the preparation of the solar selective absorption layer.Based on performing experiment,the equipment factors that affect film formation uniformity and the process factors that affect the voltage stability of the reactive sputtering AIN film layer were tested,the laws were identified,the process parameters were determined,and the application was realized through automatic feedback control.The working voltage stability of the AIN film is realized and promoted in large-scale production.Both the color and the optical performance of the vacuum tube are improved,and the quality of the vacuum tube film layer is increased.The use of B-point sputtering instead of D-site sputtering achieves voltage stabilization of the reactive sputtering of the AIN film,reduces the process time of the three-target coating machine,and increases the process efficiency by 34.2%and the production efficiency by 20%.The optimization of the length and magnetic field strength of the magnets increased the target utilization rate of 95%,achieved a good scale of economic benefits,and was well promoted in large-scale production.Some parameters were measured by using spectrophotometer,Germany Optosol detector(abbreviated as rapid measuring instrument)and other equipment:the absorbance of the products 94.3%,emission ratio of 0.064,higher than the absorption ? 94%,emission ratio ?0.08 indicators.The vacuum tube displays the same color in the upper and lower.The results of field emission scanning electron microscopy showed that the surface of the sample was a convex micro-inhomogeneous surface,which was one of the reasons for improving the absorption rate.The energy spectrum showed that the surface composition was pure;the side profile was observed at different positions of the vacuum tube,and the thickness was measured.The film thickness(upper,middle and bootom apart)of the galss tube are uniform,which are around 265 nm and meet production requirements.