Fabrication and optical behavior of AuCuSi amorphous alloy film.

Amorphous alloys are promising materials due to their unique properties and have been applied in various biomaterial coatings and micro-electro-mechanical systems. However, they have seldom been applied in the optical nano-device. Here, we systematically investigate morphology, microstructure, mechanical and optical properties of an Au-Cu-Si amorphous alloy and successfully design and fabricate a broadband optical absorber using the Au-Cu-Si amorphous alloy. Such device achieves an average absorption up to about 95% from 500 - 1500 nm with a thickness less than 300 nm. This is of significance for exploration the feasibility of amorphous alloys application in the field of optical nano-devices.