Structure and optical properties of diamond-like carbon coatings

Abstract

Using a hybrid method of cathodic arc (PVD) and chemical (CVD) deposition from the gas phase, a new type of coatings containing high amount of sp3 bonds of carbon, capable of absorbing effectively light has been developed.This thin film material is a promised one for optical devices operating in open space environment as antireflective coating for photoreceiver bodies. The hybrid method permits to obtain effective light absorbing coatings having excellent mechanical and tribological properties and is able to sustain temperature cycling in a range from plus 150 to minus 100 oC. The optical characteristics of DLC coatings were studied depending on the content of sp2bound content. The combined physical and chemical deposition of DLC coatings allows to achieve a sufficiently high light absorption (a~10 5 cm–1) and low reflection with a relatively small coating thickness about 1 mm. It has been established that the antireflective properties of such coatings depend on the conditions for their preparation, first of all on hydrocarbon gas pressure