Detection of Trace Impurity Gradients in Noble Metals by the Photothermoelectric Effect
Detection of Trace Impurity Gradients in Noble Metals by the Photothermoelectric Effect
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DOI：
10.1021/acs.jpcc.1c04927
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Charlotte I. Evans;Lucia T. Gan;Rui Yang;M. Abbasi;Xifan Wang;R. Traylor;Jonathan A. Fan;D. Natelson
中科院分区：
文献类型：
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作者：
Charlotte I. Evans;Lucia T. Gan;Rui Yang;M. Abbasi;Xifan Wang;R. Traylor;Jonathan A. Fan;D. Natelson
贵金属中的痕量杂质浓度可能对化学和物理性质产生深远的影响，但使用典型的光谱表征工具和二次离子质谱等专业技术检测这些杂质浓度仍然是一个挑战。在这项工作中，我们证明了光热电效应可以被利用来检测低浓度的铂梯度线状的金纳米结构具有高灵敏度。光热电电压测量显示，在与理论铂扩散长度一致的长度尺度上，铂杂质对金的体塞贝克系数有显着贡献。使用有限元建模，Seebeck分布计算的金铂系统，表明即使是0.01%的变化，铂浓度沿着1 μm长度的金线可以显着贡献的局部Seebeck系数。这些测量结果表明，光热电效应可以是一个高灵敏度的工具，用于检测低水平的杂质浓度在主金属线的几何形状。
Trace impurity concentrations in noble metals can have profound effects on chemical and physical properties, yet detecting these impurity concentrations remains a challenge using typical spectroscopic characterization tools and specialized techniques such as secondary ion mass spectrometry. In this work, we demonstrate that the photothermoelectric effect can be leveraged to detect low-concentration platinum gradients in wire-shaped gold nanostructures with high sensitivity. The photothermoelectric voltage measurements show significant contributions from platinum impurities to the bulk Seebeck coefficient of gold at length scales that agree with theoretical platinum diffusion lengths. Using finite element modeling, the Seebeck distribution is calculated for the gold− platinum system, showing that even a 0.01% variation in platinum concentration along a 1 μm length of gold wire can contribute significantly to the local Seebeck coefficient. These measurements indicate that the photothermoelectric effect can be a highly sensitive tool for detecting low-level impurity concentrations in host metals in a wire geometry.