Abstract
Twisted bilayer graphene (tBLG) with small twist angles has attracted significant attention because of its unique electronic properties arising from the formation of a moiré superlattice. In this study, we systematically characterized the twist-angle-dependent electronic and transport properties of tBLG grown via chemical vapor deposition. This characterization included parameters such as the charge-neutral point voltage, carrier concentration, resistance, and mobility, covering a wide range of twist angles from 0° to 30°. We experimentally demonstrated that these parameters exhibited twist-angle-dependent moiré period trends, with high twist angles exceeding 9°, revealing more practically useful features, including improved mobilities compared to those of single-layer graphene. In addition, we demonstrated that the doping states and work functions were weakly dependent on the twist angles, as confirmed by additional first-principles calculations. This study provides valuable insights into the transport properties of tBLG and its potential for practical applications in the emerging field of twistronics.
| Original language | English |
|---|---|
| Article number | 36 |
| Journal | NPG Asia Materials |
| Volume | 16 |
| Issue number | 1 |
| DOIs | |
| State | Published - Dec 2024 |
Funding
J.S.C. acknowledges support from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2021R1F1A1048196). B.H.P. was supported by the National R&D Program (No. 2022R1A2C3004135) through NRF funded by the Ministry of Science and ICT and Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education (No. 2022R1A6C101A754). Y-W.S. was supported by the National Research Foundation of Korea (NRF) (Grant No. 2017R1A5A1014862, SRC program: vdWMRC center) and KIAS individual Grant No. (CG031509). The computations were supported by the Center for Advanced Computation of KIAS. S.-H.K. was supported by the Quantum Science Center (QSC), a National Quantum Information Science Research Center of U. S. DOE. Analysis was performed by using a Witec alpha300 R at the Center for Quantum Characterization/Analysis of Two-Dimensional Materials & Heterostructures.