Iqbal Muhammad Faisal, Hussain Tanveer, Li Song, Yaqoob Manzar Mushaf, Lateef Jawad, Ying Pan, Gong Yaru, Cao Yang, Chen Guang, Tang Guodong
School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
Small. 2025 Sep;21(36):e2506235. doi: 10.1002/smll.202506235. Epub 2025 Jul 14.
Herein, a peak ZT value of ≈2 at 625 K and an average ZT of 1.46 are achieved in the AgSbTe system through band engineering and multiscale phonon scattering. This demonstrates that Ga doping achieves band convergence and an additional impurity level between the valence and conduction bands. In contrast, I and S doping contribute profound band flattening. The collective effect of band engineering yields an improved Seebeck coefficient (S) and power factor (PF). The band manipulation strategy facilitated the attainment of peak PF of 17.9 µW cm K at 625 K, and an excellent average power factor (PF) of 15.12 µW cm K is achieved for AgSbGaTeSI sample. In the meanwhile, the combined presence of coherent and incoherent nanoprecipitates introduces strong phonon scattering in AgSbTe matrix, leading to a significantly suppressed lattice thermal conductivity. The lowest lattice thermal conductivity as low as 0.31 W mK is achieved in AgSbGaTeSI sample. The vast increase of peak ZT and average ZT promotes AgSbTe as a promising candidate for widespread applications for waste heat recovery and power generation near room-temperature range (300-625 K).
在此，通过能带工程和多尺度声子散射，在AgSbTe体系中实现了625 K时约为2的峰值ZT值和1.46的平均ZT值。这表明Ga掺杂实现了能带收敛以及价带和导带之间的一个额外杂质能级。相比之下，I和S掺杂导致能带显著变平。能带工程的综合效应提高了塞贝克系数（S）和功率因子（PF）。能带调控策略促使在625 K时达到17.9 μW cm⁻² K⁻²的峰值PF，并且对于AgSbGaTeSI样品实现了15.12 μW cm⁻² K⁻²的优异平均功率因子（PF）。同时，相干和非相干纳米沉淀物的共同存在在AgSbTe基体中引入了强烈的声子散射，导致晶格热导率显著降低。在AgSbGaTeSI样品中实现了低至0.31 W m⁻¹ K⁻¹的最低晶格热导率。峰值ZT和平均ZT的大幅提高使AgSbTe成为在室温范围（300 - 625 K）附近广泛用于废热回收和发电的有前景候选材料。
