High-Performance Industrial-Grade p-Type (Bi,Sb) 2 Te 3 Thermoelectric Enabled by a Stepwise Optimization Strategy.

As the sole dominator of the commercial thermoelectric (TE) market, Bi 2 Te 3 -based alloys play an irreplaceable role in Peltier cooling and low-grade waste heat recovery. At present, the main barrier to a wider application is the relatively low efficiency determined by the low-rise TE figure of merit ZT. Herein, an effective approach is reported for improving the TE performance of p-type (Bi,Sb) 2 Te 3 by incorporating Ag 8 GeTe 6 and Se. Specifically, the diffused Ag and Ge atoms into the matrix conduce to optimized carrier concentration and enlarged the density of states effective mass while the Sb-rich nanoprecipitates generate coherent interfaces with little loss of carrier mobility. The subsequent Se dopants introduce multiple phonon scattering sources and significantly suppress the lattice thermal conductivity while maintaining a decent power factor. Consequently, a high peak ZT of 1.53 at 350 K and a remarkable average ZT of 1.31 (300-500 K) are attained in the Bi 0.4 Sb 1.6 Te 0.95 Se 0.05 + 0.10 wt% Ag 8 GeTe 6 sample. Most noteworthily, the size and mass of the optimal sample have been enlarged to Ø40 mm-200 g and the constructed 17-couple TE module exhibits an extraordinary conversion efficiency η of 6.3% at ΔT = 245 K. This work demonstrates a facile method to develop high-performance and industrial-grade (Bi,Sb) 2 Te 3 -based alloys, which paves a strong way for the further practical applications. This article is protected by copyright. All rights reserved.