Big-small size design of carbon-based multilayer films for improved wear life

Abstract

Anti-wear is an essential prerequisite for the reliability and durability of silicon-based micro/nano devices operation. To design lubricating films suitable for micro/nano devices, big-small size carbon composite multilayer films were introduced to improve wear life, which is called grain size refining effect of multilayer films. Specifically, graphene oxide (GO) nanosheets and carbon quantum dots (CQDs) were alternately spin-coated to create (GO/CQDs)n multilayer films as solid lubricant. The results show that (GO/CQDs)5 multilayer film exhibits superior wear resistance with the wear life of 9400 s under a high load of 4 N. The service life of (GO/CQDs)5 film is more than six times than that of (GO)5 film. The excellent friction performance of (GO/CQDs)5 multilayer is attributed to the layered 3D structure composed of GO nanosheets alternate with CQDs, in which the rigid GO nanosheets act the role in load-carrying capacity, and CQDs could be helpful to enhance deformation resistance of film. Meanwhile, friction-induced structural transformation makes part GO convert into graphene on sliding interface, which is benefit for reducing friction. It is expected that such multilayers will be good lubricating films for silicon-based micro/nano devices.