通过椭偏仪对生长在蓝宝石上的不同厚度氮化铝薄膜的变温光学性质进行了研究, 并采用托克-洛伦兹模型对椭偏实验数据进行了拟合分析, 精确得到了氮化铝薄膜的厚度和光学常数(折射率n, 消光系数k)等.研究的结果表明: 相比薄的氮化铝薄膜, 厚的氮化铝薄膜的折射率较大.随着温度的升高, 氮化铝的折射率、消光系数和带隙会向低能端单调地移动(红移)；厚度对带隙随温度改变的影响较小, 对折射率则有一定的影响.

We investigated the optical properties of AlN films with different thicknesses grown on sapphire by spectroscopic ellipsometry at different temperature. Based on a Tauc-Lorentz dispersion model, thickness and optical constants (the refractive index n, the extinction coefficient k) of AlN films were extracted by fitting the experimental data. Our results show that the refractive index of thicker AlN film possesses bigger values. Similar to the previous report, it was also found that the refractive index, the extinction coefficient and band gap of AlN films shift monotonously to lower energies (a redshift) with temperature increasing. Moreover, with rising temperature, varying the thicknesses of the films exhibits little influence on the shrinkage of bandgap but slight influence on the changes of the refractive index.