TY  - EJOU
AU  - Qiu, Weihang 
AU  - Zhang, Bo 
AU  - Gu, Zhaofeng 
AU  - Liu, Zijun 
AU  - Shen, Xiang 
AU  - Chen, Yimin 

TI  - Structural Relaxation and Thermal Robustness of Electron-Beam Evaporated As<sub>2</sub>Se<sub>3</sub> Films for Far-Infrared Heterogeneous Metalenses
T2  - Chalcogenide Letters

PY  - 
VL  - 
IS  - 
SN  - 1584-8663

AB  - This study presents electron-beam evaporated As<sub>2</sub>Se<sub>3</sub> films tailored for far-infrared heterogeneous metalenses. Characterization via X-ray diffraction and Raman spectroscopy reveals a structurally relaxed network in the films compared to bulk glass, resulting in enhanced infrared transmittance, a reduced refractive index, and a lower glass transition temperature. However, thermal expansion mismatch is found to induce cracking in thick films subjected to thermal cycling. The As<sub>2</sub>Se<sub>3</sub>/BaF<sub>2</sub> system demonstrates superior adhesion, attributed to a minimal thermal expansion mismatch (Δα &lt; 2.5 × 10<sup>−6</sup>°C<sup>−1</sup>). Notably, an 8 μm thick film endures over thirty rapid heating and liquid nitrogen quenching cycles without degradation, while maintaining a subwavelength thickness and optical properties suitable for metalens design. These findings establish the As<sub>2</sub>Se<sub>3</sub>/BaF<sub>2</sub> platform as a robust candidate for environmentally stable infrared heterogenous metasurfaces.
KW  - Chalcogenide As<sub>2</sub>Se<sub>3</sub> film; electron-beam evaporation; infrared metalens; structural relaxation; film adhesion

DO  - 10.32604/cl.2026.089518