Study of far-infrared Ge-Se-Te amorphous films
Abstract
<p indent="0mm">In this study, Ge<sub>20</sub>Se<sub>60</sub>Te<sub>20</sub> and Ge<sub>20</sub>Se<sub>20</sub>Te<sub>60</sub> chalcogenide glasses were synthesized using the melt quenching technique, and the amorphous chalcogenide Ge-Se-Te films with the same compositions were deposited <italic>via</italic> the method of electron beam evaporation. Together with the results of XRD, AFM, Raman spectroscopy, and Fourier transform spectroscopy, it was found that the as-deposited films can fully inherit the amorphous structures from the bulk glasses, and exhibit excellent far-infrared optical and thermal properties. Moreover, we found that the amorphous films have a subwavelength-level thickness without any defects, and low surface roughness, low optical loss, as well as the high optical refractive index. By optimizing the experimental parameters of electron beam evaporation, <sc>~8 μm</sc> thick Ge<sub>20</sub>Se<sub>20</sub>Te<sub>60</sub> films can be deposited efficiently and controllably, with a high refractive index of ~3.12, low extinction coefficient (< 0.015), and an average optical transmittance of ~70%, in the range of <sc>8–14 μm.</sc> The development of this amorphous film is beneficial in the research of far-infrared photonic devices, and can be used for applications such as far-infrared heterogeneous metalenes.</p>
