Abstract
Magnesium Silicide is one of the interesting thermoelectric materials known for relative abundance of its constituents, thermal stability, non-toxicity and environmental friendly nature. In this paper we have theoretically studied Bi doped Mg2Si. The electronic structure calculations predict non-existence of the energy gap for Mg2Si1-xBix with (0.125 <= x <= 0.5). It has been found that the system with x=0.125 exhibits highest Seebeck coefficient and electrical conductivity. Due to low thermal conductivity at x=0.125, Mg2Si0.875Bi0.125 attained maximum value of dimensionless figure of merit 0.67 at 1200 K. With increase in concentration of Bi, the value of figure of merit decreases.