New PM route via bulk mechanical alloying is developed to fabricate the solid solution semi-conductive materials with and for 0 < x, y < 1 and to investigate their thermoelectric materials. Since is n-type and both and are p-type, pn-transition takes place at the specified range of germanium content, x, and tin content, y. Through optimization of chemical composition, solid-solution type thermoelectric semi-conductive materials are designed both for n-and p-type materials.