▎ 摘　　要

NOVELTY - Preparing single crystal graphene comprises: vapor depositing a single crystal metallic film on a single mica substrate by an electron beam evaporation plating method using a metal evaporation source; vacuumizing the deposited film at 3Pa, introducing hydrogen gas and argon, and then raising a temperature to 850-1000?; raising the temperature to 1000 degrees C after the heat treatment is finished, continuously introducing methane gas with hydrogen gas and argon; and closing a heating power supply after the deposition is finished, stopping the methane gas with hydrogen gas and hydrogen, and cooling. USE - The method is useful for preparing a single crystal graphene (claimed). ADVANTAGE - The single crystal graphene has large size, high quality and less defect, and can be prepared in a cost-effective manner. DETAILED DESCRIPTION - Preparing low cost large size single crystal graphene comprises: vapor depositing a single crystal metallic film on a single mica substrate by an electron beam evaporation plating method using a metal evaporation source at a high vacuum environment of 1x 10-3-1x 10-4 Pa, where evaporation rate is 0.02-0.20 nm/s, a substrate temperature is 450-650 degrees C, and the metallic film has a thickness of 500-1000 nm; vacuumizing the deposited film at 3Pa, introducing hydrogen gas and argon, where the rate of hydrogen gas flow is 50 standard cubic centimeters per minute (sccm), the rate of argon flow is 10 sccm, and the working pressure is 1x 105 Pa, and then raising a temperature to 850-1000 degrees C, where the heat treatment time is 30-120 minutes; raising the temperature to 1000 degrees C after the heat treatment is finished, continuously introducing methane gas with hydrogen gas and argon, where the methane flow rate is 0.5-10 sccm, the hydrogen flow rate is 10-50 sccm, the argon flow rate is 800-1000 sccm, the working pressure is 105 Pa, and the deposition time is 5-30 minutes; and closing a heating power supply after the deposition is finished, stopping the methane gas with hydrogen gas and hydrogen, rapidly cooling to a room temperature, where the cooling speed is 10 degrees C/seconds, and obtaining uniform growth of high quality silicon single crystal graphene.