Laser-assisted synthesis of graphene from pitch
A method for synthesizing graphene includes depositing pitch on a substrate to provide a pitch sample, and pyrolyzing at least a portion of the pitch sample with a laser, thereby forming graphene. A method for upgrading pitch includes providing a pitch sample under vacuum, and irradiating the pitch with a laser to form an upgraded pitch product. A system for synthesizing graphene includes a pitch deposition system configured to deposit pitch on a substrate to form a deposited pitch sample, and a laser irradiation system. The laser irradiation system includes a laser comprising an outlet for a beam of light, and a substrate holding area in line with the outlet of the laser. The laser irradiation system is capable of transforming at least a portion of the deposited pitch sample to form graphene.
1 . A method for synthesizing graphene, the method comprising:
depositing pitch on a substrate to provide a pitch sample; and
pyrolyzing at least a portion of the pitch sample with a laser, thereby forming graphene,
wherein pyrolyzing the at least a portion of the pitch sample with the laser comprises directly irradiating the at least a portion of the pitch sample with an excimer laser, and
wherein the excimer laser emits light having a wavelength in a range from 300 to 320 nm and a frequency in a range from 45 to 55 HZ.
2 . The method of claim 1 , wherein the depositing comprises:
spin-coating the pitch sample on the substrate to form a uniformly coated pitch sample.
3 . The method of claim 1 , prior to pyrolyzing the at least a portion of the pitch sample, further comprising:
removing one or more atmospheric gases from the pitch sample with a vacuum; and
introducing an inert gas to the pitch sample.
4 . The method of claim 3 , wherein pyrolyzing the at least the portion of the pitch sample is performed under vacuum.
5 . The method of claim 1 , wherein the laser has a laser pulse energy in a range from 290 to 310 mJ.
6 . The method of claim 1 , wherein irradiating the at least a portion of the pitch sample comprises irradiating the at least a portion of the pitch sample with an excimer laser for a period of time in a range from 1 minute to 10 minutes.