Figure 2: Microstructure characterization of graphene and converted h-BN.
From: Direct chemical conversion of graphene to boron- and nitrogen- and carbon-containing atomic layers
(a) and (d) Schematic of graphene and h-BN. The carbon, nitrogen and boron atoms are in grey, blue and green, respectively. (b) An atomic resolution (Scanning transmission electron microscopy- annular dark field) STEM-ADF image of the graphene sample before conversion. (c) A corresponding EEL (electron energy loss) spectrum of graphene. (e) Atomic resolution STEM-ADF image of highly crystallized double layer h-BN converted from graphene. The darker area in the centre corresponds to single-layered h-BN, showing the presence of single-nitrogen atom (brighter one) and boron atom (darker one); this is further verified by intensity profile (inset in Fig. 2f) of the atoms across the yellow-dashed line shown in (e). (f) A corresponding EEL spectra of the converted h-BN. The scale bar for both (b) and (e) is 0.5 nm.
