Condensed point defects enhance thermoelectric performance of rare-earth Lu-doped GeTe

• DOI: 10.1016/j.jmst.2023.01.004
• Publication Date: 2023-02-09T09:23:17Z
• Authors: Wan-Yu Lyu; Wei-Di Liu; Meng Li; Xiao-Lei Shi; Min Hong; Tianyi Cao; Kai Guo; Jun Luo; Jin Zou; Zhi-Gang Chen
• Keywords: Electronegativity; Atomic radius

Heavy rare-earth element doping can effectively strengthen phonon scattering, suppress the lattice thermal conductivity, and enhance overall thermoelectric performance of GeTe. However, large electronegativity difference between elements (such as La, Eu, Gd) Ge refrains limit below 1 mol.% in Here, compared with other rare earth elements, Lu was found to have a relatively small radius Ge, which induce high level The result shows that reduces conductivity from 0.77 W m−1 K−1 GeTe 0.35 Ge0.98Lu0.02Te at 673 K, further induces zT value 1.5 K. Extra Sb alloying optimizes carrier concentration 1.02 × 1021 cm−3 1.77 1020 Ge0.90Lu0.02Sb0.08Te, results reasonable power factor 33.82 µW cm−1 K−2 low electrical 0.75 K Ge0.90Lu0.02Sb0.08Te. Correspondingly, peak 1.75 an average 0.92 within temperature range 303–723 are obtained Ge0.9Lu0.02Sb0.08Te. This study indicates co-doping boost GeTe-based materials.