SUPERLATTICE STRUCTURES PARTICULARLY SUITABLE FOR USE AS THERMOELECTRIC COOLING MATERIALS

摘要

A superlattice comprising alternating layers of (PbTeSe).sub.m and (BiSb).sub.n (where m and n are the number of PbTeSe and BiSb monolayers per superlattice period, respectively) having engineered electronic structures for improved thermoelectric cooling materials (and other uses) may be grown by molecular beam epitaxial growth. Preferably, for short periods, n+m 50. However, superlattice films with 10,000 or more such small periods may be grown. For example, the superlattice may comprise alternating layers of (PbTe.sub.1-z Se.sub.z).sub.m and (Bi. sub. x Sb.sub.1-x).sub.n. According to a preferred embodiment, the superlattice comprises a plurality of layers comprising m layers of PbTe. sub.0.8 Se.sub.0.2 and n layers of Bi.sub.0.9 Sb.sub.0.1, where m and n are preferably between 2 and 20.