This invention describes thin film (AgSbTe2)1-x(GeTe)x (GAST) and AgxPbTe materials for improved thermoelectric proerties. The thin film GAST materials are p-type nano-structured semiconductors and the AgxPbTe films are n-type materials. The films are used in single layer, quantum well, superlattice, and segmented thermoelectric power generating structures. They are deposited on polyimide, metal, ceramic or semiconductor substrates.