Fig. 1: Lateral heterostructure spectroscopy and microscopy.

a Schematic representation of the MoSe2-WSe2 LH, encapsulated in hBN. Grey, orange and red spheres represent Mo, W and Se atoms, respectively. b HAADF-STEM image showing a MoSe2-WSe2 boundary (between the red lines). The MoSe2 and WSe2 areas are located between the yellow and the cyan lines, respectively. c Corresponding PL (black) and reflectance contrast (red) spectra of MoSe2 (top) and WSe2 (bottom). The PL linewidth of neutral excitons (A1s) is 7 meV in MoSe2 and 5.5 meV in WSe2.