Thermoelectric properties of Mn-doped ZnSbs fabricated without sintering process

ZnSb, a promising thermoelectric material, has traditionally been fabricated using a high-temperature sintering process. In the present study, we developed a compaction technology that eliminates the need for sintering, aiming to establish a more efficient fabrication for the ZnSb-based bulks. The thermoelectric properties of Mn-doped ZnSb samples (Zn_1-xMn_xSb, x = 0, 0.0025, 0.0050, 0.0075, 0.010) fabricated by the compaction technology were evaluated through their electronic and thermal transport properties over a temperature range of 50 to 200 °C. Both pristine ZnSb and Mn-doped ZnSbs exhibited p-type conduction behavior. The electrical conductivity of ZnSb was significantly enhanced by doping of 0.75 at% Mn at Zn-site mainly due to the improved carrier mobility, which leads to large power factor enhancement to 0.089 mW/mK² for 0.75 at% Mn-doped ZnSb. Consequently, more than 300% enhancement in the dimensionless figure-of-merit (zT) with a peak zT value of 0.08 was achieved in 0.75 at% Mn-doped ZnSb at 473 K.