Strain-induced electronic structure and functionality changes in 2D Materials - Understanding the nanomechanical underlying mechanisms governing strain engineering

Dr. Santiago D. Solares
Professor, St. Albert the Great Chair in Engineering
Department of Mechanical Engineering
The Catholic University of America

Wed, January 17, 2024 - 4:00 PM

santiago-solares-sm.jpgTwo-dimensional (2D) materials offer technologically relevant properties such as strong light–matter interactions and tunability of their electronic structure. For example, the band gap of MoTe2 can be modulated by 0.2 eV through the application of linear strain (Figure 1A [1]), which can potentially enable applications based on technologically relevant light wavelengths. In the past, changes in electronic structure have also been demonstrated in other 2D materials, such as in the reversible generation of quantum dots in graphene though application of axisymmetric strain via a scanning tunneling microscope probe (Figure 1B and C [2]). Strain engineering thus offers opportunities for designing new and exotic nanoelectronic systems. However, the determination and application of the appropriate strain field on specific discrete 2D structures is by no means a trivial matter. In the above studies strain has emerged naturally from the experimental geometry, offering little control and therefore little opportunity for precise engineering design. This talk discusses the two mechanisms for strain generation introduced above for graphene and MoTe2, as well as the prospects for more intricate strain designs enabled by, (i) understanding of the fundamental quantitative relationships between strain changes and electronic structure changes, as well as (ii) harnessing of specific nanoscale mechanical behaviors (Figure 1D, [3]).



Refreshments served at 3:45 PM

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