Remote epitaxy. (A) Schematic of the effect of the layer number of 2D materials on screening potential field from substrates. Comparison of the transparency of (B) graphene (Gr) and (C) h-BN with different layer numbers [45]. (D) High angle annular dark field scanning transmission electron microscopy (HAADF-STEM) images of the interfaces with monolayer and bilayer graphene [43]. (E) Geometric phase analysis e_xx mappings of the interface of AlGaN/sapphire without and with Gr [43]. (F) Fluctuation of in-plane lattice mismatch of nitride with respect to sapphire and in-plane lattice mismatch of strain-free AlGaN with respect to sapphire and AlGaN/sapphire without and with Gr, respectively [43]. (G) Schematic of the effects of 2D materials on nucleation and diffusion. E_ad, adsorption energy. (H) Diagram of the bonding of an Al adatom to pyrrolic N defect on graphene introduced by N₂ plasma treatment [9]. Diffusion barriers of Al adatoms (I) on sapphire substrate and (J) graphene across different adsorption sites [47]. (K) Scanning electron microscopy (SEM) image of the AlN domains on sapphire and Gr/sapphire, respectively [40]. (L) SEM images of AlN membranes on the nanopatterned sapphire substrate (NPSS) without and with Gr [47]. (M) HAADF-STEM image of the Gr/Al₂O₃ interface [48]. The scale bar in (M) is 0.5 nm.