SiGe alloys have been fabricated with the hiqghest carrier concentrations achieved to date. Values in excess of 4.0 × 1020 have been observed. The thermoelectric behavior of these samples has been characterized, both in the as-pressed state and as a function of 3anneal time and temperature. Figures-of-merit between 0.85 and 0.90 × 10−3 K−1 have been reproducibly achieved. Further improvements will be achieved by reducing the carrier concentration.