The Lightest 2D Nanomaterial: Freestanding Ultrathin Li Nanosheets by in-situ Electron Microscopy

• DOI: 10.48550/arxiv.2010.03786
• Publication Date: 2020-01-01
• Authors: Sun, Muhua; Stolte, Nore; Wang, Jianlin; Wei, Jiake; Chen, Pan; Zhao, Yu; Xu, Zhi; Wang, Wenlong; Pan, Ding; Bai, Xuedong
• Keywords: 0301 basic medicine; Chemical Physics (physics.chem-ph); Condensed Matter - Materials Science; 03 medical and health sciences; Physics - Chemical Physics; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences

Lithium (Li) is the simplest metal and the lightest solid element. Here we report the first demonstration of controlled growth of two-dimensional (2D) ultrathin Li nanosheets with large lateral dimensions up to several hundreds of nanometres and thickness limited to just a few nanometres by in-situ transmission electron microscopy (TEM). The nanoscale dynamics of nanosheets growth were unravelled by real-time TEM imaging, which, in combination with density function theory (DFT) calculations indicates that the growth of bcc structured Li into 2D nanosheets is a consequence of kinetic control as mediated by preferential oxidization of the (111) surfaces due to the trace amount of O2 (~10-6 Pa) within TEM chamber. The plasmonic optical properties of the as-grown Li nanosheets were probed by cathodoluminescence (CL) spectroscopy equipped within TEM, and a broadband visible emission was observed that contains contributions of both in-plane and out-of-plane plasmon resonance modes.