二氧化钒薄膜用于激光防护时膜层厚度的计算

VO2膜作为相变温度最接近室温的热致相变材料,相变前透过率高,探测器可正常工作,吸收来袭激光能量相变后透过率低,起到保护探测器作用,可用在激光防护领域。膜层厚度对透过率有很大影响,采用吸收膜的特征矩阵方法加以分析,通过VO2膜的折射率及消光系数等光学参数,计算出薄膜相变前后透过率。按照符合透过率相变前75%,相变后5%的薄膜,计算出厚度,结合对溅射产额和溅射速率的计算,可得到制备时间。在硒化锌基片上制备了VO2膜,用红外分光光度计测量出相变前后透过率为79.2%和12.3%。样品经轮廓仪测量得到的厚度与计算得到的厚度基本相符。

Thin Films Thickness Calculation of Vanadium Dioxide Using as Laser Protection Material

Vanadium dioxide thin films can be used in laser protection for it has the closest phase transition temperature to the room temperature. Before phase transition, its transmittance is high, and the detector can work. Phase transition occurs when the attack laser′s energy is absorbed, then transmittance decrease, and the detector can be protected. The film thickness has large influence on transmittance. Its influence can be analyzed by eigenmatrix method of absorbing thin film, calculating the transmittance before and after phase transition using refract index n and extinction index k. For the transmittance 75% before and 5% after phase transition by calculating the thickness, combining with the calculation of sputtering yield and sputtering rate, preparing time can be gotten. VO2 thin films were prepared on zinc selenide, the transmittance was measured by IR spectrophotometer, 79.2% before and 12.3% after phase transition. The thickness was measured by profile meter, and the result fits the calculation well. The calculation about thickness is doable.