Increased thermoelectric performance by Cl doping in nanostructured AgPb18SbSe20-xClx

The quaternary AgPb18SbTe20 (LAST) alloy is well known for having low thermal conductivity and high ZT. Nano-precipitates of AgSbTe2 contribute significantly to the decrease of the lattice thermal conductivity. In this work, Te was completely substituted by the more economically available Se in LAST. Low thermal conductivity was achieved in AgPb18SbSe20 (LASS) made by melting and hot pressing. We subsequently studied the thermoelectric properties of LASS with different dopants, and found Cl was effective in increasing the carrier concentration and power factor, which enhanced ZT to similar to 1.3 in n-type AgPb18SbSe19.928Cl0.072 at about 873 K. Published by Elsevier Ltd.