Thus far, the field of topological insulators has been focused on bismuth and antimony chalcogenide based materials such as Bi 2 Se 3, Bi 2 Te 3, Sb 2 Te 3 or Bi 1 − x Sb x, Bi 1.1 Sb 0.9 Te 2 S. The choice of chalcogenides is related to the van der Waals relaxation of the lattice matching strength which restricts the number of materials and substrates. Bismuth chalcogenides have been studied extensively for TIs and their applications in thermoelectric materials. The van der Waals interaction in TIs exhibit important features due to low surface energy. For instance, the surface of Bi 2 Te 3 is usually terminated by Te due to its low surface energy.