Title of the project: Atomic scale modifications of heteronanostructures under extreme conditions
Name of the VDSP student: Heena Inani
Project supervised by: Jani Kotakoski

My research work is basically to observe the structural transformation of stacked systems of multidimensional materials under external stimuli i.e. joule heating, ion and electron irradiation. Here, I am referring the structure to an atomic structure i.e. imaging an individual atom or an arrangement of atoms in the materials. In our lab, we have the one of the best scanning transmission electron microscope (STEM) which allows us to image the atomic structure. While I absolutely enjoy looking at atoms and their dynamics on computer screen in lab, in free time I like to travel, do yoga and go for bike-ride in city.

My research focuses on to observe the structural evolution and modify the properties of 2D materials (graphene, MoS2) and their stacked systems under external stimuli such as joule heating, highly charged ions and plasma irradiation. For example, the ions with high charge states could modify the structure of materials by depositing their energy in materials and hence allows us to selectively modify the material with specific energy and charge state. So, in a bilayer MoS2/graphene system, here we present a STEM image of bilayer MoS2 with twist angle of ~8.6 degree and thus forming nicely visible moire pattern in which intensity of atoms are related to their atomic number, as for Mo (high) and S (low). In the middle of the image, we have created a nano-size pore selectively in one layer of bilayer (beneath the pore monolayer MoS2 structure is visible) by bombarding the material with 50 keV Xe+38 ions.

Kotakoski group