Electron-Beam-Induced Synthesis of Hexagonal 1H-MoSe₂ from Square β-FeSe Decorated with Mo Adatoms

Journal Article · 31 January 2018 · Nano Letters

DOI: https://doi.org/10.1021/acs.nanolett.7b05457 · OSTI ID:1484761

Brehm, John A.  ^[1]; Lin, Junhao  ^[2]; Zhou, Jiadong ^[3]; Sims, Hunter ^[1]; Liu, Zheng  ^[4]; Pantelides, Sokrates T. ^[5]; Suenaga, Kazu ^[6]

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1. Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics and Astronomy; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
2. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan)
3. Nanyang Technological Univ. (Singapore). Center for Programmable Materials, School of Materials Science and Engineering
4. Nanyang Technological Univ. (Singapore). Center for Programmable Materials, School of Materials Science and Engineering, Centre for Micro-/Nano-electronics (NOVITAS), School of Electrical & Electronic Engineering
5. Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics and Astronomy, and Dept. of Electrical Engineering and Computer Science; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
6. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Univ. of Tokyo (Japan). Dept. of Mechanical Engineering

Two-dimensional (2D) materials have generated interest in the scientific community because of the advanced electronic applications they might offer. Powerful electron beam microscopes have been used not only to evaluate the structures of these materials but also to manipulate them by forming vacancies, nanofragments, and nanowires or joining nanoislands together. In this work, we show that the electron beam in a scanning transmission electron microscope (STEM) can be used in yet another way: to mediate the synthesis of 2D 1H-MoSe₂ from Mo-decorated 2D β-FeSe and simultaneously image the process on the atomic scale. This is quite remarkable given the different crystal structures of the reactant (square lattice β-FeSe) and the product (hexagonal lattice 1H-MoSe₂). Herein, the feasibility of the transformation was first explored by theoretical calculations that predicted that the reaction is exothermic. Furthermore, a theoretical reaction path to forming a stable 1H-MoSe₂ nucleation kernel within pure β-FeSe was found, demonstrating that the pertinent energy barriers are smaller than the energy supplied by the STEM electron beam.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Vanderbilt Univ., Nashville, TN (United States)
• Sponsoring Organization: Japan Society for the Promotion of Science (JSPS); National Research Foundation Singapore (NRF); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21)
• Grant/Contract Number: AC02-05CH11231; FG02-09ER46554
• OSTI ID: 1484761
• Journal Information: Nano Letters, Journal Name: Nano Letters Journal Issue: 3 Vol. 18; ISSN 1530-6984
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English