Spectroscopic signatures of edge states in hexagonal boron nitride
h-BN, edge structure, spectroscopic signatures, electron energy-loss near edge structure
We use Z-contrast imaging and atomically resolved electron energy-loss spectroscopy on an aberration-corrected scanning transmission electron microscope to investigate the local electronic states of boron atoms at different edge structures in monolayer and bilayer h-BN. We find that edges with bonding unsaturated sp2 boron atoms have a unique spectroscopic signature with a prominent pre-peak at ~ 190.2 eV in the B K-edge fine structure. First-principles calculations reveal that the observed pre-peak arises from excitations to the in-plane lowest-energy empty sp2 boron dangling bonds at the B-terminated edge. This spectroscopic signature can serve as a fingerprint to explore new edge structures in h-BN.
Tsinghua University Press
Chuang Gao,Lei Tao,Yu-Yang Zhang,Shixuan Du,Sokrates T. Pantelides,Juan Carlos Idrobo,Wu Zhou,Hong-Jun Gao, Spectroscopic signatures of edge states in hexagonal boron nitride. NanoRes.2019, 12(7): 1663–1667