| AVS 60th International Symposium and Exhibition | |
| Graphene and Other 2D Materials Focus Topic | Thursday Sessions |
| Session GR+EM+NS+SS+TF-ThA |
| Session: | Beyond Graphene: Other 2D Electronic Materials and their Heterostructures |
| Presenter: | N.P. Guisinger, Argonne National Laboratory |
| Authors: | A.J. Mannix, Northwestern University B.T. Kiraly, Northwestern University M.C. Hersam, Northwestern University N.P. Guisinger, Argonne National Laboratory |
| Correspondent: | Click to Email |
Recent experimental evidence suggests that silicene, the silicon analog to graphene, exhibits a Dirac cone band structure[1,3], low temperature superconductivity[2], and Dirac Fermion chirality[3]. These discoveries highlight silicene’s potential as a platform for novel electronics and physical phenomena. Depending on the growth parameters, silicon deposition on Ag(111) produces several distinct monolayer silicene phases corresponding to different silicon buckling configurations. Although these phases are well documented, their defect structure remains uninvestigated. Using ultra-high vacuum scanning tunneling microscopy (UHV STM), the structural and electronic properties of edges and defects within these various silicene phases were probed. Several highly-bucked phases are shown to exhibit electronically active domain boundaries, edges, and/or point defects, but do not show evidence of scattering. On the other hand, the lightly buckled honeycomb phase demonstrates clear, bias-dependent electronic scattering from edges and point defects. These contrasting behaviors suggest fundamental differences in charge transport properties that are of great interest to further silicene development. Additional insight is derived from the structure and electronic characteristics of the 0D and 1D defects, which often play a dominant role in determining material properties.
[1] Vogt, P., De Padova, P., Quaresima, C., Avila, J., Frantzeskakis, E., Asensio, M., … Le Lay, G. (2012). Silicene: Compelling Experimental Evidence for Graphene-like Two-Dimensional Silicon. Physical Review Letters, 108(15), 155501. doi:10.1103/PhysRevLett.108.155501
[2] Chen, L., Feng, B., & Wu, K. (2013). Observation of a possible superconducting gap in silicene on Ag(111) surface. Applied Physics Letters, 102(8), 081602. doi:10.1063/1.4793998
[3] Feng, B., Li, H., Liu, C., Shao, T.-N., Cheng, P., Yao, Y., Wu, K. (2013). Observation of Dirac Cone Warping and Chirality Effects in Silicene. ACS Nano. doi:10.1021/nn403661h