Figure 1: STXM mapping of the electronic structure of graphene.
From: Imaging local electronic corrugations and doped regions in graphene
STXM images and data of CVD grown SLG on Cu after wet etching in HNO3 and transfer. (a) Transmission mode data is converted to OD by I/I0, where I0 is measured in an empty scan region; summation of 0.3 eV energy steps is normalized to carbon at 320 eV. Corresponding white intensity describes the thickness and morphology of the graphene sheet. The scale bar is 1 μm and the total distance across the image is 4 μm. (b) Integrated C K-edge spectrum of entire image in (a). The electromagnetic field vector (E) and incident X-ray photon energy (hν) are at angle (θ). The angular difference between the pristine basal plane (blue π orbitals) and the asperity (red π orbitals) represent a degree of corrugation (φ) of a rippled graphene sheet. (c) Isolated C K-edge spectra of each region displayed in (a), where spectra D and F displayed in the inset have the most prominent pre-edge features. The pre-edge feature is further clearly discernible in Figures 2 and 3.
