Chemical Research in Chinese Universities ›› 2023, Vol. 39 ›› Issue (4): 690-696.doi: 10.1007/s40242-023-3120-3

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Heavy Rare Earth Element Gd Enhancing Thermoelectric Performance in p-Type Polycrystalline SnSe via Optimizing Carrier Transport and Density of States

XU Pengfei, HUA Yezhen, JIN Kangpeng, XU Biao   

  1. School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
  • Received:2023-05-11 Online:2023-08-01 Published:2023-07-18
  • Contact: XU Biao E-mail:xubiao@njust.edu.cn
  • Supported by:
    This work was supported by the Central University Basic Research Fund of China (No.30922010201).

Abstract: Tin selenide(SnSe) material exhibits very excellent thermoelectric properties in both p- and n-type single crystals, benefiting from advantageous electronic structure and ultra-low lattice thermal conductivity. However, poor mechanical properties and time-consuming production limit its practical application, and polycrystalline SnSe has attracted great attention in recent years. Herein, the SnSe microplates are prepared by a facile solvothermal method and compacted by spark plasma sintering (SPS). With enhanced electrical conductivity(σ) and optimized Seebeck coefficient(S) benefited from the Sn vacancies and increased density of states effective mass by the incorporating of heavy rare earth element Gd, an enhanced power factor(PF) value of about 0.86 mW/(m·K2) is realized in the p-type polycrystalline Sn0.985Gd0.015Se sample. Combined with the medium total thermal conductivity κtot and lattice thermal conductivity κlat of 0.7 and 0.56 W/(m·K), respectively, an enhanced peak dimensionless figure of merit(ZT) of ca. 1.1 was achieved at 873 K along vertical to the SPS pressing direction. The average ZT was also improved as compared to that of the pristine SnSe sample.

Key words: Thermoelectric, SnSe, Gd, Doping