PREPARATION AND THERMOELECTRIC PROPERTIES OF MG2SI1-XGEX (X=0.0-SIMILAR-TO-0.4) SOLID-SOLUTION SEMICONDUCTORS

Mg2Si1-xGex Solid Solution Semiconductors were prepared in the composition range 0.0 less-than-or-equal-to x less-than-or-equal-to 0.4. At a composition x=0.4, effects of impurities were investigated for dopants of Sb and Ag. Carrier concentrations were controlled up to 1.5 x 10(26) electrons/m3 and 5.5 x 10(25) holes/m3 by doping Sb and Ag, respectively. The thermal conductivity kappa was measured at 300 K. By calculating the electronic thermal conductivity kappa(el) based on the Fermi integration, the lattice thermal conductivity kappa(ph) was estimated to be 2.10 Wm-1 K-1. Figure-of-merits Z's of Mg2Si0.6Ge0.4 at 300 K were 0.69 x 10(-3) K-1 for the n-type sample with an electron concentration of 5.4 x 10(25) m-3 (3000 ppmSb) and 0.47 x 10(-3) K-1 for the p-type one with a hole concentration of 5.2 x 10(25) m-3 (16000 ppmAg).