Achieving a High zTavg in n-Type Sb-Doped Mg2Si0.3Sn0.7 via High-Pressure-Modulated Microstructures DOI

Xiangyang Dong,

Rongwei Zhai, Bowen Zheng

et al.

ACS Applied Materials & Interfaces, Journal Year: 2025, Volume and Issue: unknown

Published: March 26, 2025

Mg2Si-based compounds are cost-effective and environmentally friendly thermoelectric materials. However, the current Mg2(Si,Sn) solid solutions still suffer from low figure of merit zT (or energy conversion efficiency), especially averaged value (zTavg < 1.0). In this study, we synthesize Mg2(Si0.3Sn0.7)1–xSbx (x = 0, 0.5, 0.75, 1, 1.5%) through combination high-pressure, high-temperature (HPHT) synthesis spark plasma sintering (SPS). The high-pressure instrument effectively inhibits unfavorable oxidation Mg. This HPHT + SPS methodology improves defect formation efficiency Sb-doped Mg2Si0.3Sn0.7, leading to an increased carrier concentration enhanced electrical conductivity. Moreover, as a benefit pressure-induced conduction band convergence Sb-flattened band, density states' effective mass (md*) significantly increases ∼3.3me, maintaining high Seebeck coefficients even at concentration. synergetic effects doping md* increase peak power factor exceed 50 μW cm–1 K–2. Notably, due HPHT-modified microstructures, hierarchy phonon scatterings established suppress lattice thermal conductivity 1.29 W m–1 K–1 568 K; Sb point defects, dislocations, grain boundaries/pores can scatter short-, medium-, long-wavelength phonons, respectively. Ultimately, optimized Mg2(Si0.3Sn0.7)0.99Sb0.01 sample in whole temperature region; is 1.37 673 K, plateau ∼1.35 realized between 723 K. Thus, notable average over range 323–723 K 1.08. Our work demonstrates that high-pressure-induced concentration, doping, microstructure modifications facilitate property improvement Mg2(Si,Sn)-based compounds.

Language: Английский

Enhancing thermoelectric properties of crystalline silicon through high energy heavy ion irradiation DOI
Kelin Zhu, Aoran Fan, Jianguang Wang

et al.

Applied Surface Science, Journal Year: 2025, Volume and Issue: unknown, P. 162757 - 162757

Published: Feb. 1, 2025

Language: Английский

Citations

0
Achieving a High zTavg in n-Type Sb-Doped Mg2Si0.3Sn0.7 via High-Pressure-Modulated Microstructures DOI

Xiangyang Dong,

Rongwei Zhai, Bowen Zheng

et al.

ACS Applied Materials & Interfaces, Journal Year: 2025, Volume and Issue: unknown

Published: March 26, 2025

Mg2Si-based compounds are cost-effective and environmentally friendly thermoelectric materials. However, the current Mg2(Si,Sn) solid solutions still suffer from low figure of merit zT (or energy conversion efficiency), especially averaged value (zTavg < 1.0). In this study, we synthesize Mg2(Si0.3Sn0.7)1–xSbx (x = 0, 0.5, 0.75, 1, 1.5%) through combination high-pressure, high-temperature (HPHT) synthesis spark plasma sintering (SPS). The high-pressure instrument effectively inhibits unfavorable oxidation Mg. This HPHT + SPS methodology improves defect formation efficiency Sb-doped Mg2Si0.3Sn0.7, leading to an increased carrier concentration enhanced electrical conductivity. Moreover, as a benefit pressure-induced conduction band convergence Sb-flattened band, density states' effective mass (md*) significantly increases ∼3.3me, maintaining high Seebeck coefficients even at concentration. synergetic effects doping md* increase peak power factor exceed 50 μW cm–1 K–2. Notably, due HPHT-modified microstructures, hierarchy phonon scatterings established suppress lattice thermal conductivity 1.29 W m–1 K–1 568 K; Sb point defects, dislocations, grain boundaries/pores can scatter short-, medium-, long-wavelength phonons, respectively. Ultimately, optimized Mg2(Si0.3Sn0.7)0.99Sb0.01 sample in whole temperature region; is 1.37 673 K, plateau ∼1.35 realized between 723 K. Thus, notable average over range 323–723 K 1.08. Our work demonstrates that high-pressure-induced concentration, doping, microstructure modifications facilitate property improvement Mg2(Si,Sn)-based compounds.

Language: Английский

Citations

0