Ta2O5薄膜是可见光到近红外波段中重要的高折射率薄膜材料之一。本文针对离子束溅射制备Ta2O5薄膜的光学带隙特性开展了实验研究工作, 基于Cody-Lorentz模型表征了薄膜的光学带隙特性, 重点针对薄膜的禁带宽度和Urbach带尾宽度与制备参数之间的相关性进行研究。研究结果表明: 在置信概率95%以上时, 对Ta2O5薄膜禁带宽度影响的制备参数, 权重大小依次为氧气流量、基板温度、离子束电压; 而对Ta2O5薄膜Urbach带尾宽度影响的制备参数, 权重大小依次为基板温度和氧气流量。对于Ta2O5薄膜在超低损耗激光薄膜和高损伤阈值激光薄膜领域内应用, 本文的研究结果给出了同步提高薄膜的禁带宽度和降低带尾宽度的重要工艺参数选择方法。

The Ta2O5 thin film is one of the most important high refractive materials in the range from visible to near infrared. This paper researched the optical band gap of the Ta2O5 thin film which was deposited by the Ion Beam Sputtering (IBS). The optical band gap was characterized by the Cody-Lorentz dispersion model. Particularly, the correlations of the band gap and the Urbach with technological parameters were studied respectively. The results show that when the confidence probability is over 95%, the technological parameters are ranked due to their influence coefficients on the band gap as follows: oxygen flow, substrate temperature, and ion beam voltage. Accordingly due to those on the Urbach, the technological parameters are ranked as substrate temperature and oxygen flow. The result provides a method for choosing the key technological parameters to increase the band gap width and reduce the Urbach energy width simultaneously of the Ta2O5 thin film used in the areas of the ultra-low loss thin film and high laser-induced damage threshold thin film.