Composition Control and Thermoelectric Properties of Quaternary Chalcogenide Nanocrystals: The Case of Stannite Cu2CdSnSe4
Composition Control and Thermoelectric Properties of Quaternary Chalcogenide Nanocrystals: The Case of Stannite Cu2CdSnSe4
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DOI：
10.1021/cm2031812
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发表时间：
2012-02-14
影响因子：
8.6
通讯作者：
Cabot, Andreu
中科院分区：
文献类型：
--
作者：
Ibanez, Maria;Cadavid, Doris;Cabot, Andreu
提出了一种用于生产具有窄尺寸分布和精确控制的组成的四元I-2-II-IV-VI 4纳米晶体，特别是亚锡酸盐Cu 2 + xCd 1-xSnSe 4的高产率和可升级的胶体合成路线。这里还示出了如何在组成元素中的化合价的多样性允许通过调整阳离子比率来有效地控制它们的电导率。同时，虽然四元硫族化物的晶体学复杂性与固有的低热导率相关联，但晶格尺寸减小到纳米级进一步降低了材料的热导率。在亚锡酸盐晶体结构的特定情况下，价带最大态的方便的板状分布允许p型电导率与塞贝克系数和热导率两者的部分解耦。结合这些特征，我们展示了如何初始优化的纳米晶体镉/铜的比例，使我们能够获得低温溶液处理的材料与ZT值高达0.71在685 K
A high-yield and upscalable colloidal synthesis route for the production of quaternary I-2-II-IV-VI4 nanocrystals, particularly stannite Cu2+xCd1-xSnSe4, with narrow size distribution and precisely controlled composition is presented. It is also shown here how the diversity of valences in the constituent elements allows an effective control of their electrical conductivity through the adjustment of the cation ratios. At the same time, while the crystallographic complexity of quaternary chalcogenides is associated with intrinsically low thermal conductivities, the reduction of the lattice dimensions to the nanoscale further reduces the materials thermal conductivity. In the specific case of the stannite crystal structure, a convenient slab distribution of the valence band maximum states permits a partial decoupling of the p-type electrical conductivity from both the Seebeck coefficient and the thermal conductivity. Combining these features, we demonstrate how an initial optimization of the nanocrystals Cd/Cu ratio allowed us to obtain low-temperature solution-processed materials with ZT values up to 0.71 at 685 K