Speaker
Description
Over the years, the study of bent and curved geometries in nanomaterials [1] has remained of great interest to researchers, as it provides a new platform for investigating fundamental physical properties such as mechanical deformation led generation of pseudo-electric and magnetic fields [2,3] or introducing strain via curvature-induced molecular adsorbates on a graphene sheet [4]. However, the effect of geometrical curvature on the energy levels of nanoscale materials remains an open question. In this project, using scanning tunnelling microscopy (STM) and spectroscopy (STS) measurements, we have demonstrated that in ultrathin CdSe nanoplatelets exhibit a significant variation in the location of conduction and valence band edges and their difference i.e. band gap as a function of curvature from the edge to the centre of the nanoplatelet. Our experimental findings, supported by theoretical calculations, reveal that the higher band gap at the edge, compared to the centre of the nanoplatelet is associated with the larger magnitude of curvature between the edge and the centre. These scientific findings open a new avenue for studying electron transport at the nanoscale influenced by curved geometries.
References:
[1] Lilian Guillemeney, Laurent Lermusiaux, Guillaume Landaburu, Benoit Wagnon, Benjamin Abécassis, Curvature and self-assembly of semi-conducting nanoplatelets, Communications Chemistry 5, 7 (2022). https://doi.org/10.1038/s42004-021-00621-z
[2] M. M. Fogler, F. Guinea, and M. I. Katsnelson, Pseudomagnetic Fields and Ballistic Transport in a Suspended Graphene Sheet, Physics Review Letter 101, 226804 (2008). https://doi.org/10.1103/PhysRevLett.101.226804
[3] N. Levy, S. A. Burke, K. L. Meaker, M. Panlasigui, A. Zettl, F. Guinea, A. H. Castro Neto, M. F. Crommie, Strain-Induced Pseudo–Magnetic Fields Greater Than 300 Tesla in Graphene Nanobubbles, Science 329, 544 - 547 (2010). https://doi.org/ 10.1126/science.1191700
[4] Simon A. Svatek, Oliver R. Scott, Jasmine P.H. Rivett, Katherine Wright, Matteo Baldoni, Elena Bichoutskaia, Takashi Taniguchi, Kenji Watanabe, Alexander J. Marsden, Neil R. Wilson,and Peter H. Beton, Adsorbate-Induced Curvature and Stiffening of Graphene, Nano Letters 15, 159 - 164 (2015). https://doi.org/10.1021/nl503308c
| Apply for student award at which level: | None |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |
