Extended Data Fig. 4: Epitaxial relationship of the TI thin films grown on a single surface of suspended graphene substrates.
From: Double-sided van der Waals epitaxy of topological insulators across an atomically thin membrane
a–c, Plan-view SAED patterns of the Bi2Se3 thin film grown on the top surface of suspended graphite (a), the Bi2Se3 thin film grown on the bottom surface of suspended monolayer graphene (b), and the Sb2Te3 thin film grown on the top surface of suspended monolayer graphene (c). Insets: Plan-view TEM BF images. The white solid circles and the yellow dashed circles indicate the areas in which the SAED in the corresponding main panels are taken and the suspended regions, respectively. The entire area displayed in the inset is suspended for a. Scale bars in the insets: 1 μm (a), 200 nm (b), and 200 nm (c). All data (a–c) exhibit the preferential epitaxial relationship of \({\{10\bar{1}0\}}_{{{\rm{Bi}}}_{2}{{\rm{Se}}}_{3}\,{{\rm{or}}\,{\rm{Sb}}}_{2}{{\rm{Te}}}_{3}}\parallel {\{10\bar{1}0\}}_{{\rm{graphene}}\,{\rm{or}}\,{\rm{graphite}}}\), indicating that the epitaxial alignment in the double-sided vdW epitaxy is owing to the local interaction at the interface with the suspended vdW substrate layer.
