Progress towards the preparation of (TiTe/sub 2/)/sub 3/(Bi/sub 2/Te/sub 3/)/sub y/(TiTe/sub 2/)/sub 3/(Sb/sub 2/Te/sub 3/)/sub z/ superlattices

Abstract

Superlattices based on the thermoelectric standard compounds Bi/sub 2/Te/sub 3/ and Sb/sub 2/Te/sub 3/ demonstrate enhanced ZT values. The formation of the superlattice (Bi/sub 2/Te/sub 3/)/sub x/(Sb/sub 2/Te/sub 3/)/sub y/ through the modulated elemental reactants (MER) approach is hindered by interdiffusion of the Bi/sub 2/Te/sub 3/ and Sb/sub 2/Te/sub 3/ layers at the necessary annealing temperatures. TiTe/sub 2/ has the potential to act as a diffusion barrier between the Bi/sub 2/Te/sub 3/ and Sb/sub 2/Te/sub 3/ layers of the superlattice. (TiTe/sub 2/)/sub 3/(Bi/sub 2/Te/sub 3/)/sub y/(TiTe/sub 2/)/sub 3/(Sb/sub 2/Te/sub 3/)/sub z/ superlattices were synthesized using the MER approach, successfully separating the different V-VI layers by TiTe/sub 2/. This study shows that the number of Bi/sub 2/Te/sub 3/ and Sb/sub 2/Te/sub 3/ layers can be precisely controlled using the MER method.