A simplistic and improved technique was employed for type-II Ge clathrate film fabrication on the sapphire substrate. This method involves the deposition of metal Na layer onto amorphous Ge film and subsequent annealing for several hours by an infrared lamp heater under high vacuum in the same chamber. X-ray diffraction and Raman measurements confirmed the synthesis of type II Ge clathrate film and the crystallographic parameters were refined by Rietveld analysis. Scanning electron micrographs revealed the sample to be 1.2 μm thick and granular film with a lot of cracks. Nevertheless, the sample appeared homogeneous and uniform with the naked eye and the optical transmission spectrum indicated periodic fluctuation due to the light interference.

在蓝宝石衬底上制造 II 型 Ge 包合物薄膜时采用了一种简化和改进的技术。该方法包括将金属 Na 层沉积到非晶 Ge 膜上，然后在同一腔室中在高真空下通过红外灯加热器退火数小时。X 射线衍射和拉曼测量证实了 II 型 Ge 包合物膜的合成，并且晶体学参数通过 Rietveld 分析进行了改进。扫描电子显微照片显示样品为 1.2 μm 厚的颗粒状薄膜，有很多裂纹。尽管如此，样品在肉眼下表现出均质和均匀，并且由于光干涉，光透射光谱显示出周期性波动。