The Scanning Transmission Electron Microscope as a Platform for Atomic Scale Synthesis

The scanning transmission electron microscope (STEM), a workhorse instrument in materials characterization, can not only be used to observe dynamic processes with atomic resolution, but also <i>drive and control synthesis with atomic precision</i>. Through custom control of the electron beam position that actively feeds back on image, spectroscopy, and other data streams, it’s possible to use focused beam energy to precisely initiate and interrupt desired transformations. This can be used for generating point defects, drilling and milling materials, changing phase, modifying bond coordination, and positioning dopants. Furthermore, control over the local environment through custom MEMS devices for heating and biasing, <i>in situ</i> evaporators, and laser irradiation, provides means to dose the sample with thermal energy, optical excitation, and reactant or dopant materials to provide the proper conditions for reactions and transformations to occur. Finally, to close the loop, the STEM can then be used in its more traditional characterization modes to image transformation processes as they occur and assess if new functional properties emerge. Presented here are recent results highlighting advancements towards such a “synthescope”[1] including new insights gained by studying the generation and temperature dependent diffusion of beam-generated single vacancies in suspended 2D materials [4,5], strategies to restrict vacancy diffusion so they can serve as sites for dopant insertion, demonstration of patterning of arrays of dopants [3], and the delivery of dopant atoms to the sample, in situ [2]. Development of this combination of experimental methods provides a window into the dynamic synthesis processes at fundamental length scales and a path towards fabricating materials and devices with atomically precise components for potential quantum information science applications. <br/> <br/>This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, and was performed at the Center for Nanophase Materials Sciences (CNMS), a U.S. Department of Energy, Office of Science User Facility.<br/><br/> <br/>1. Dyck, O., Lupini, A. R. , <b><u>Jesse, S</u></b>. "<i>The Synthescope: A Vision for Combining Synthesis with Atomic Fabrication</i>". <b><i>Advanced Materials</i></b> (2023, 2023 Aug) https://doi.org:10.1002/adma.202301560<br/>2. Dyck, O., Lupini, A. R. , <b><u>Jesse, S</u></b>. "<i>A Platform for Atomic Fabrication and In Situ Synthesis in a Scanning Transmission Electron Microscope</i>". <b><i>Small Methods</i></b> (2023, Jul) https://doi.org:10.1002/smtd.202300401<br/>3. Dyck, O., Yeom, S., Lupini, A. R., Swett, J. L., Hensley, D., Yoon, M. , <b><u>Jesse, S</u></b>. "<i>Top-Down Fabrication of Atomic Patterns in Twisted Bilayer Graphene</i>". <b><i>Advanced Materials</i></b> (2023, Jun) https://doi.org:10.1002/adma.202302906<br/>4. Boebinger, M. G., Brea, C., Ding, L. P., Misra, S., Olunloyo, O., Yu, Y. L., Xiao, K., Lupini, A. R., Ding, F., Hu, G. X., Ganesh, P., <b><u>Jesse, S</u></b>. , Unocic, R. R. "<i>The Atomic Drill Bit: Precision Controlled Atomic Fabrication of 2D Materials</i>". <b><i>Advanced Materials</i></b> <b>35</b> (2023, Apr) https://doi.org:10.1002/adma.202210116<br/>5. Dyck, O., Yeom, S., Dillender, S., Lupini, A. R., Yoon, M. , <b><u>Jesse, S</u></b>. "<i>The role of temperature on defect diffusion and nanoscale patterning in graphene</i>". <b><i>Carbon</i></b> <b>201</b>, 212-221 (2023, Jan) https://doi.org:10.1016/j.carbon.2022.09.006