Silver content dependent thermal conductivity and thermoelectric properties of electrodeposited antimony telluride thin films
Silver content dependent thermal conductivity and thermoelectric properties of electrodeposited antimony telluride thin films
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DOI：
10.1038/s41598-019-45697-9
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发表时间：
2019-06-25
影响因子：
4.6
通讯作者：
Lee, Jaeho
中科院分区：
文献类型：
--
作者：
Ferrer-Argemi, Laia;Yu, Ziqi;Lee, Jaeho
虽然含银的电沉积碲化锑薄膜表现出良好的热电性能，但其热导率和银含量依赖性仍然未知。在这里，我们报告了 Ag3.9Sb33.6Te62.5 和 AgSbTe2 薄膜在受控退火和温度条件下的热导率，并证明了银含量对热传输的影响。经过160℃退火后，Ag3.9Sb33.6Te62.5和AgSbTe2薄膜的室温导热系数分别从0.24 Wm(-1) K-1增加到1.59 Wm(-1) K-1和0.17 Wm(-1) K-1增加到0.56 Wm(-1) K-1。使用声子输运模型和 X 射线衍射测量，我们将热导率的增加归因于晶体生长，并解释了热导率随结晶程度的变化。与之前研究中报道的电性能不同，银含量的存在对Ag3.9Sb33.6Te62.5的热导率影响很小，并导致AgSbTe2薄膜的热导率大幅降低。通过在94℃下进行瞬态热导率测量，我们发现Ag3.9Sb33.6Te62.5和AgSbTe2薄膜的结晶活化能分别为1.14 eV和1.16 eV。它们的差异揭示了银在抑制 Sb2Te3 晶体的成核和生长以及阻碍热传输方面的作用。这些发现为优化近室温热电应用碲化锑的掺杂和退火条件提供了指导。
While electrodeposited antimony telluride thin films with silver contents demonstrated promising thermoelectric properties, their thermal conductivity and the silver content dependence remain unknown. Here, we report the thermal conductivities of Ag3.9Sb33.6Te62.5 and AgSbTe2 thin films with controlled annealing and temperature conditions and demonstrate the impact of silver content on thermal transport. After annealing at 160 degrees C, the room-temperature thermal conductivity of Ag3.9Sb33.6Te62.5 and AgSbTe2 thin films increases from 0.24 to 1.59 Wm(-1) K-1 and from 0.17 to 0.56 Wm(-1) K-1, respectively. Using phonon transport models and X-ray diffraction measurements, we attribute the thermal conductivity increases to the crystal growth and explain the thermal conductivity variations with the degree of crystallization. Unlike electrical properties reported in previous studies, the presence of silver contents has little impact on the thermal conductivity of Ag3.9Sb33.6Te62.5 and leads to a strong reduction in the thermal conductivity of AgSbTe2 thin films. By performing transient thermal conductivity measurements at 94 degrees C, we find the crystallization activation energy of Ag3.9Sb33.6Te62.5 and AgSbTe2 films as 1.14 eV and 1.16 eV, respectively. Their differences reveal the role of silver in inhibiting the nucleation and growth of Sb2Te3 crystals and impeding thermal transport. These findings provide guidance for optimizing doping and annealing conditions of antimony tellurides for near-room-temperature thermoelectric applications.