Nature Communications (Sep 2024)

Carrier-phonon decoupling in perovskite thermoelectrics via entropy engineering

  • Yunpeng Zheng,
  • Qinghua Zhang,
  • Caijuan Shi,
  • Zhifang Zhou,
  • Yang Lu,
  • Jian Han,
  • Hetian Chen,
  • Yunpeng Ma,
  • Yujun Zhang,
  • Changpeng Lin,
  • Wei Xu,
  • Weigang Ma,
  • Qian Li,
  • Yueyang Yang,
  • Bin Wei,
  • Bingbing Yang,
  • Mingchu Zou,
  • Wenyu Zhang,
  • Chang Liu,
  • Lvye Dou,
  • Dongliang Yang,
  • Jin-Le Lan,
  • Di Yi,
  • Xing Zhang,
  • Lin Gu,
  • Ce-Wen Nan,
  • Yuan-Hua Lin

DOI
https://doi.org/10.1038/s41467-024-52063-5
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 12

Abstract

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Abstract Thermoelectrics converting heat and electricity directly attract broad attentions. To enhance the thermoelectric figure of merit, zT, one of the key points is to decouple the carrier-phonon transport. Here, we propose an entropy engineering strategy to realize the carrier-phonon decoupling in the typical SrTiO3-based perovskite thermoelectrics. By high-entropy design, the lattice thermal conductivity could be reduced nearly to the amorphous limit, 1.25 W m−1 K−1. Simultaneously, entropy engineering can tune the Ti displacement, improving the weighted mobility to 65 cm2 V−1 s−1. Such carrier-phonon decoupling behaviors enable the greatly enhanced μ W/κ L of ~5.2 × 103 cm3 K J−1 V−1. The measured maximum zT of 0.24 at 488 K and the estimated zT of ~0.8 at 1173 K in (Sr0.2Ba0.2Ca0.2Pb0.2La0.2)TiO3 film are among the best of n-type thermoelectric oxides. These results reveal that the entropy engineering may be a promising strategy to decouple the carrier-phonon transport and achieve higher zT in thermoelectrics.