Universal dry synthesis and patterning of high-quality and -purity graphene quantum dots by ion-beam assisted chemical vapor deposition. (January 2022) - Ha, Jun Mok
Abstract: A synthesis and patterning process of luminescent graphene quantum dots (GQDs) is highly desirable in applications to industrial- and bio-fields. In this paper, a novel strategy to obtain GQDs is proposed and demonstrated by an ion-beam assisted chemical vapor deposition (CVD). Ion-beam irradiation provides catalyst sources for the GQD creation. The luminescent GQDs are generated using a Fe-implanted Si wafer by a two-step annealing process: i) A formation step of nano-sized Fe catalyst particles and ii) a synthesis step of GQDs by a CVD method. Under the 1st annealing step of the Fe-implanted Si wafer, Fe nanoparticles (FeNPs) are created by the diffusion and aggregation of Fe atoms. Due to the high temperature atmosphere in the 2nd annealing step, FeNPs are then completely removed, and thus only high-purity and -quality GQDs are finally produced. In our work, patterned GQDs were fabricated by using a metallic mask during the ion-beam irradiation. Furthermore, various GQD patterns were also demonstrated by combining the conventional semiconductor manufacturing process and our ion-beam assisted CVD technique. Graphical abstract: Image 1