In 2008, researchers at Purdue University, along with collaborators from other institutions, developed a method to synthesize high-quality graphene by surface segregation on nickel (Ni) surfaces and transferring it to insulating substrates. The process involved dissolving carbon in Ni at high temperatures and then cooling it at controlled rates. Different cooling rates affected the thickness and quality of the graphene films. Medium cooling rates produced high-quality, well-controlled-thickness graphene films, which were then transferred to insulating substrates via wet etching without losing their quality, as confirmed by Raman spectroscopy. Graphene, a two-dimensional material, has attracted significant interest due to its potential in electronics and materials science. However, large-scale synthesis of high-quality graphene remains a challenge. The study demonstrated that controlling the cooling rate during the segregation process allows for the production of several layers of high-quality graphene on Ni substrates. The optimal cooling rate was found to be medium, which allowed for the segregation of a finite amount of carbon at the surface, resulting in high-quality graphene films. The process involved heating Ni foils in an inert gas atmosphere, introducing hydrocarbon gases to dissolve carbon into the Ni, and then cooling the samples at different rates. The cooling rate significantly influenced the amount and quality of carbon segregated at the Ni surface. A medium cooling rate (10°C/s) produced high-quality graphene with few layers, while faster cooling rates led to the formation of graphite with more defects. The study also showed that transferring the graphene from Ni to insulating substrates, such as glass, maintained its high quality. The transferred graphene was transparent and could be distinguished from the silicone rubber used in the transfer process using Raman spectroscopy. The results indicate that controlled surface segregation with optimized cooling rates can produce high-quality, low-cost graphene suitable for practical electronic applications. The research was supported by the National Science Foundation (NSF) and the Center for Advanced Materials at the University of Houston.In 2008, researchers at Purdue University, along with collaborators from other institutions, developed a method to synthesize high-quality graphene by surface segregation on nickel (Ni) surfaces and transferring it to insulating substrates. The process involved dissolving carbon in Ni at high temperatures and then cooling it at controlled rates. Different cooling rates affected the thickness and quality of the graphene films. Medium cooling rates produced high-quality, well-controlled-thickness graphene films, which were then transferred to insulating substrates via wet etching without losing their quality, as confirmed by Raman spectroscopy. Graphene, a two-dimensional material, has attracted significant interest due to its potential in electronics and materials science. However, large-scale synthesis of high-quality graphene remains a challenge. The study demonstrated that controlling the cooling rate during the segregation process allows for the production of several layers of high-quality graphene on Ni substrates. The optimal cooling rate was found to be medium, which allowed for the segregation of a finite amount of carbon at the surface, resulting in high-quality graphene films. The process involved heating Ni foils in an inert gas atmosphere, introducing hydrocarbon gases to dissolve carbon into the Ni, and then cooling the samples at different rates. The cooling rate significantly influenced the amount and quality of carbon segregated at the Ni surface. A medium cooling rate (10°C/s) produced high-quality graphene with few layers, while faster cooling rates led to the formation of graphite with more defects. The study also showed that transferring the graphene from Ni to insulating substrates, such as glass, maintained its high quality. The transferred graphene was transparent and could be distinguished from the silicone rubber used in the transfer process using Raman spectroscopy. The results indicate that controlled surface segregation with optimized cooling rates can produce high-quality, low-cost graphene suitable for practical electronic applications. The research was supported by the National Science Foundation (NSF) and the Center for Advanced Materials at the University of Houston.