Application of diamond-like carbon film as protection and antireflection coatings of ZnS elements

Abstract

In the present study, the rf plasma chemical vapor deposition technique is applied to directly deposit a diamond-like carbon (DLC) film onto a zinc sulfide (ZnS) substrate with excellent adhesion. Great attention is paid to the investigation of the correlation between the deposition process parameters and the structure and properties of DLC film, and of the optical spectrum characteristic of DLC films appropriate to protect IR window materials. The experimental results show that the refractive index, microhardness, and growth rate of DLC films increase with increasing dc bias voltage. The IR transmittance of the ZnS substrate with DLC film has been increased to some extent between 3 and 12 μm.