Optical and Mechanical Properties of ZnS/Ge0.1C0.9 Antireflection Coating on Ge Substrate

In this work, we designed, fabricated, and characterized a ZnS single-layer antireflection coating on Ge substrate, suitable for infrared range. To improve the coatings hardness, Ge0.1C0.9 film was deposited on the prepared coating. Y2O3 thin film was applied as adhesive layer between the ZnS film/Ge substrate and the Ge1-xCx film/ZnS film. The morphology and surface roughness of the samples were studied by FE-SEM and AFM analyses. The optical and mechanical properties of the resultant multilayer sample were investigated. The results showed that Ge0.1C0.9 coating does not change the refractive index of the antireflection coating. The indentation test showed that the hardness is improved from 5.9 to 7.8 GPa. After coating Ge0.1C0.9 layer, the sample successfully passed the environmental and durability tests.

Automated summary

A ZnS single-layer antireflection coating on Ge substrate suitable for the infrared range was designed, fabricated, and tested for hardness improvement. The sample passed environmental and durability tests after the deposition of Ge0.1C0.9 film.