Thermoelectric Properties of Bismuth Telluride Thin Films Electrodeposited from a Nonaqueous Solution
Thermoelectric Properties of Bismuth Telluride Thin Films Electrodeposited from a Nonaqueous Solution
复制标题
DOI：
10.1021/acsomega.0c01284
复制
发表时间：
2020-06-23
期刊：
影响因子：
4.1
通讯作者：
de Groot, C. H. Kees
中科院分区：
文献类型：
--
作者：
Cicvaric, Katarina;Meng, Lingcong;de Groot, C. H. Kees
报道了在弱配位溶剂二氯甲烷（CH_2Cl_2）中电沉积Bi_2Te_3薄膜的热电性能。结果表明，多孔薄膜的氧化严重，导致其热电性能下降。我们表明，可以通过施加短的初始成核脉冲，产生大量的核，然后通过脉冲电沉积在一个低得多的过电位生长的核，膜的形态得到显着改善。这显著地减少了膜的氧化，因为光滑膜具有较小的表面积与体积比并且不易于氧化。X射线光电子能谱（XPS）表明，这些薄膜与Te（O）终端显示出完全没有氧低于表面层。开发了一种薄膜转移工艺，使用聚苯乙烯作为载体聚合物，将薄膜从导电TiN转移到绝缘层，用于热电特性。温度依赖的Seebeck测量显示，室温系数为-51.7 μ V/K，在520 ℃时增长到近-100 μ V/K。在该温度下，相应的功率因数达到88.2 μ W/mK（2）。
We report the thermoelectric properties of Bi2Te3 thin films electrodeposited from the weakly coordinating solvent dichloromethane (CH2Cl2). It was found that the oxidation of porous films is significant, causing the degradation of its thermoelectric properties. We show that the morphology of the film can be improved drastically by applying a short initial nucleation pulse, which generates a large number of nuclei, and then growing the nuclei by pulsed electrodeposition at a much lower overpotential. This significantly reduces the oxidation of the films as smooth films have a smaller surface-to-volume ratio and are less prone to oxidation. X-ray photoelectron spectroscopy (XPS) shows that those films with Te(O) termination show a complete absence of oxygen below the surface layer. A thin film transfer process was developed using polystyrene as a carrier polymer to transfer the films from the conductive TiN to an insulating layer for thermoelectrical characterization. Temperature-dependent Seebeck measurements revealed a room-temperature coefficient of -51.7 mu V/K growing to nearly -100 mu V/K at 520 degrees C. The corresponding power factor reaches a value of 88.2 mu W/mK(2) at that temperature.