| AVS 66th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology Division | Thursday Sessions |
| Session NS+2D+QS-ThM |
| Session: | Direct Atomic Fabrication by Electron and Particle Beams & Flash Session |
| Presenter: | Chuanxu Ma, Oak Ridge National Laboratory |
| Authors: | C. Ma, Oak Ridge National Laboratory Z. Xiao, North Carolina State University J. Huang, Oak Ridge National Laboratory L. Liang, Oak Ridge National Laboratory W. Lu, North Carolina State University K. Hong, Oak Ridge National Laboratory B.G. Sumpter, Oak Ridge National Laboratory J. Bernholc, North Carolina State University A.-P. Li, Oak Ridge National Laboratory |
| Correspondent: | Click to Email |
Precision control of interfacial structures and electronic properties is the key to the realization of functional heterostructures. Here, utilizing the scanning tunneling microscope (STM) both as a manipulation and characterization tool, we demonstrate the fabrication of a heterostructure in a single atomically precise graphene nanoribbon (GNR) and report its electronic properties1. The heterostructure is made of a seven-carbon-wide armchair GNR (7-aGNR) and a lower band gap intermediate ribbon synthesized bottom-up from a molecular precursor on an Au substrate. The short GNR segments are directly written in the ribbon with an STM tip to form atomic precision intraribbon heterostructures. Based on STM studies combined with density functional theory calculations, we show that the heterostructure has a type-I band alignment, with manifestations of quantum confinement and orbital hybridization. We further investigate the negative differential resistance (NDR) devices using the GNR heterostructure based double-barrier models2. Our computational results indicate that nanoscale engineering for NDR needs to consider atomic size effect in design and atomic precision in fabrication. This combined theoretical-experimental approach opens a new avenue for the design and fabrication of nanoscale devices with atomic precision.
References
1. Ma, C.; Xiao, Z.; Huang, J.; Liang, L.; Lu, W.; Hong, K.; Sumpter, B. G.; Bernholc, J.; Li, A.-P. Direct writing of heterostructures in single atomically precise graphene nanoribbons. Phys. Rev. Materials 2019, 3, 016001.
2. Xiao, Z.; Ma, C.; Huang, J.; Liang, L.; Lu, W.; Hong, K.; Sumpter, B. G.; Li, A. P.; Bernholc, J. Design of Atomically Precise Nanoscale Negative Differential Resistance Devices. Adv. Theory Simul. 2018, 2, 1800172.