Progress towards the preparation of (TiTe2)3(Bi2Te3)y(TiTe2)3(Sb2Te3)z superlattices

Superlattices based on the thermoelectric standard compounds Bi₂Te₃ and Sb₂Te₃ demonstrate enhanced ZT values. The formation of the superlattice (Bi₂Te₃)_x(Sb₂Te₃)_y through the modulated elemental reactants (MER) approach is hindered by interdiffusion of the Bi₂Te₃ and Sb₂Te₃ layers at the necessary annealing temperatures. TiTe₂ has the potential to act as a diffusion barrier between the Bi₂Te₃ and Sb₂Te₃ layers of the superlattice. (TiTe₂)₃(Bi₂Te₃)_y(TiTe₂)₃(Sb₂Te₃)_z superlattices were synthesized using the MER approach, successfully separating the different V-VI layers by TiTe₂. This study shows that the number of Bi₂Te₃ and Sb₂Te₃ layers can be precisely controlled using the MER method.