Reaction temperature and time dependence of MoCl₅ intercalation to few-layer graphene

The efficient MoCl₅ intercalation process is required to reduce the resistance of graphene interconnects. We found that optimum intercalation temperature and time depends on the layer number of few-layer graphene. The bilayer graphene was intercalated at 175 °C without serious damage, besides that higher temperature of 200 °C was required to intercalate tri-layer graphene (TLG) with a fixed reaction time for 60 min. Although we can reduce the intercalation temperature for TLG, longer reaction time is required and higher damage is found. After considering both viewpoint of the effective doping and low damage, the high reaction temperature with short reaction time condition may be suitable for the TLG intercalation process. The stacked upper layer is considered to protect the underlying layer from chemical damage during the intercalation process and it leads to the higher activation energy for intercalation at the same time. Therefore, higher reaction temperature or longer reaction time are required for intercalating FLG with more layer numbers.