Effects of antimony content in MgAg0.97Sbx on output power and energy conversion efficiency

We report the effect of Sb content in MgAg0.97Sbx (x = 0.99, 0.9925, 0.995, and 1.00) on output power and leg efficiency. Due to the doubling of carrier concentration with increasing the Sb content, power factor is enhanced around 20% over the whole temperature range. Simultaneously, the average thermoelectric figure of merit (ZT) is even enhanced a little in spite of the increased corresponding thermal conductivity. We further calculated the engineering power factor (PF)(eng), output power, engineering figure of merit (ZT)(eng) and leg efficiency by taking into account of the Thomson effect. Assuming T-c = 300 K and T-h = 548 K, leg length similar to 2 mm, an output power of similar to 1.77 W cm(-2) and leg efficiency eta of similar to 10.1% are finally obtained for the optimized composition MgAg0.97Sb0.995. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.