Cooling rate and energy dependence of pulsed laser fabricated graphene on nickel at reduced temperature

Few-layer graphene was fabricated on nickel substrates using pulsed laser deposition at a relatively low temperature of 750 °C. The effects of cooling rate and laser energy on the ability to produce crystalline graphene layers were studied. It was observed that using a cooling rate of 1 and 50 °C/min produced few-layer graphene while the latter gave less defects. Laser energy was a less critical factor as long as the laser energy was below 100 mJ, however a higher laser energy was detrimental to the precipitation process. The mechanisms behind the observation of such phenomena are explained.