Additional file 1: Figure S1. Scalable synthesis of monolayer WSe2 on sapphire: influence on (a) concentration of the seeding promoters and (b) temperature for the WSe2 growth. Figure S2. Synthesis of the laterally stitched graphene-WS2: (a) optical and (b)AFM image of the graphene-WS2 and (c) PL spectrum of the WS2. Raman mapping of (d) the E2g mode of WS2 and (e) the G’ mode of graphene. (f) PL mapping of the Graphene-WS2. (Scale bar: 4 μm).