We demonstrated the generation of a bandgap in the bilayer graphene synthesized by plasma-enhanced chemical vapor deposition. By adjusting the growth time, the defect density and nano-crystallite size of bilayer graphene were easily controlled, affecting the bandgap of bilayer graphene and the field effect mobility of bilayer graphene field effect transistor (FET). The defect density increased with increasing growth time, whereas the nano-crystallite size decreased. The semiconducting behavior of bilayer graphene was observed by measuring the temperature-dependent conductivity. Defects generated by plasma radiation induce broken symmetry in graphene, thus opening a bandgap. The bandgap energies in the bilayer graphene are 90, 156, and 187 meV for growth times of 5, 10, and 30 min, respectively. The back-gate bilayer graphene FET presented the p-type semiconducting behavior and the field effect mobility of approximately 1000 cm2 V-1 s-1 when the bandgap energy was 156 meV.
Bibliographical noteFunding Information:
This work was supported by the World Class University project ( WCU, R32-2008-000-10082-0 ), the International Cooperation of Science &Technology project ( KICOS, 2009-00299 ), and the Basic Science Research Program ( NRF-2013R1-A1A2008875 ) through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology , and it was also supported by the Korea Basic Science Institute .
- Semiconducting behavior
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering