Fig. 1: Design of hexagonal boron nitride (hBN) nanostructures and photoemission electron microscopy (PEEM) methods.
a Schematic of a dielectric waveguide with an hBN flake on glass substrate with ~10 nm indium tin oxide (ITO) layer for avoiding surface charging in PEEM experiments. n0, n1 and n2 denote the refractive indexes of materials. b Schematic of PEEM measurements with a laser beam at normal incidence. Ev and Evac denote the valence band and vacuum level, respectively, and hν denote the photon energy. c Optical image of a typical hBN nanostructure. d Corresponding PEEM image excited with a 410-nm laser with right-handed circular polarization (RCP) at normal incidence.
