Ramzan Muhammad, Rana Anwar M, Hafeez Muhammad, Ahmed Ejaz, Bhatti Arshad S, Wasiq Muhammad F, Nadeem Muhammad Y
Acta Chim Slov. 2014;61(1):80-6.
We report on HfO2/Al/HfO2 multilayer thin films for heat mirror applications prepared on corning glass substrates by electron beam evaporation. Films fabricated at a substrate temperature of 100 °C show nano-polycrystals of HfO2 embedded in a disordered lattice according to X-ray diffraction results. Atomic force microscopy revealed that HfO2/Al/HfO2 layers possess smooth surface that is appropriate for optical heat mirror applications. Study of optical properties by UV-Visible spectrophotometer demonstrated that transmittance of HfO2/Al/HfO2 device was decreasing from UV to VIS and then slightly increasing in the NIR regions, with an opposite trend followed by reflectance. Optical constants i.e. refractive index, extinction coefficient, band gap energy, Urbach energy has also been calculated. The optical band gap and Urbach energy are found to be 4.34 eV and 3.164 eV, respectively. The collective oscillation energy loss for heat mirrors applications are also observed.
我们报道了通过电子束蒸发在康宁玻璃基板上制备的用于热镜应用的HfO2/Al/HfO2多层薄膜。根据X射线衍射结果，在100°C基板温度下制备的薄膜显示出嵌入无序晶格中的HfO2纳米多晶体。原子力显微镜显示，HfO2/Al/HfO2层具有适合光学热镜应用的光滑表面。通过紫外-可见分光光度计对光学性质的研究表明，HfO2/Al/HfO2器件的透过率从紫外区域到可见区域逐渐降低，然后在近红外区域略有增加，反射率则呈现相反的趋势。还计算了光学常数，即折射率、消光系数、带隙能量、乌尔巴赫能量。发现光学带隙和乌尔巴赫能量分别为4.34 eV和3.164 eV。还观察到了用于热镜应用的集体振荡能量损失。
