A Study On Graphene Films Preparation And Healing Of Reduced Graphene Oxide Films By Plasma-enhanced Chemical Vapor Deposition

Graphene is a novel two-dimensional atomic thin crystalline nanomaterial and it shows spectacular optoelectronic properties as a result of its unique structure.Graphene has been attracting tremendous attention all round the world since it was discovered and it has been considered to be one of the most promising materials for transparent conductive films?TCFs?.In terms of the preparation of graphene films,it is mainly composed of wet and dry method.Wet method includes spin coating,spraying,filtration deposition and so on.Its advantages are simple preparation and low cost and drawback is the defective films of poor conductivity.Dry method which is the chemical vapor deposition?CVD?method is mature but the cost is high.Aimed at the shortcomings of dry and wet method,this paper studies the preparation of graphene films of high quality and healing of RGO films by plasma-enhanced chemical vapor deposition?PECVD?,and also the properties of graphene films.In this paper,PECVD is first used to prepare graphene films.In the formation of graphene,plasma can enhance the activity of reactants,reduce the reaction temperature and shorten the reaction time,and have the ability to directly form graphene films on the dielectric substrate,which has great help for the future industrial production of graphene TCFs.In this paper,the optimized process parameters for the preparation of graphene films by PECVD were explored by the system research.Lower temperature and the introduction of hydrogen are beneficial for the preparation of graphene films of higher quality.On the other hand,the healing of RGO to prepare graphene films is adopted in this paper.RGO films are a very defective form of graphene by wet method.Thermal chemical vapor deposition?CVD?,plasma enhanced CVD?PECVD?,and high temperature graphitization have been reported to convert RGO to high-quality graphene by repair defects in RGO.Among those,PECVD can lower the temperature of healing RGO to 560 ?.However,controllability and deep understanding of healing RGO with PECVD have rarely been reported.In this paper,hydrogen is introduced into the pure methane plasma and the equilibrium between etching and healing of RGO by PECVD is observed.The results show that hydrogen plays an important role in the inhibition of amorphous carbon formation in the healing of RGO films and the most efficient healing occurs at the temperature slightly above the healing-etching equilibrium temperature.In addition,first-principles calculations reveal that the repair of defects is dominated by reactions between dangling bonds and CH and CH₂ radicals in the plasma in this paper.Although there is still a long time for the industrial application of graphene films,it is expected to obtain large-size graphene TCFs of high quality and bring a breakthrough for the preparation and application of graphene of excellent properties along with the further study of the growth mechanism of graphene and RGO recovery mechanism.