Abstract Electrodeposition is an efficient wet-chemical approach to reduce the manufacturing cost of thin films. However, the thin films fabricated using this approach show properties inferior to those of the thin films fabricated using dry processes. In this study, a titanium nitride (TiN) diffusion barrier layer was formed on a stainless-steel (SS) substrate to improve the thermoelectric properties of electrodeposited Bi2Te3 thin films. The electrodeposition of the Bi2Te3 films was carried out in the potentiostatic mode using a standard three-electrode cell, followed by thermal annealing at 300–500°C. The X-ray diffraction and electron probe X-ray microanalysis results revealed that impurity diffusion from the SS substrate did not occur in the annealed films deposited on the TiN-coated SS substrate. However, the Bi2Te3-to-Bi4Te5 crystalline phase transformation occurred at higher annealing temperatures because of the preferential evaporation of Te atoms from the film surface, leading to the deterioration of the thermoelectric properties of the films. As a result, the 300°C-annealed film formed on the TiN-coated SS substrate showed the highest power factor of 4.4 μW/(cm·K2), which is approximately four times higher than that of the corresponding film formed on the bare SS substrate. Therefore, the TiN coating and optimum annealing temperature improved the thermoelectric properties of the electrodeposited Bi2Te3 thin films.

中文翻译：

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在不锈钢衬底上使用 TiN 扩散阻挡层和热退火增强电沉积 Bi2Te3 薄膜的热电性能

摘要 电沉积是一种有效的湿化学方法，可以降低薄膜的制造成本。然而，使用这种方法制造的薄膜表现出低于使用干法制造的薄膜的性能。在这项研究中，在不锈钢 (SS) 衬底上形成氮化钛 (TiN) 扩散阻挡层，以提高电沉积 Bi2Te3 薄膜的热电性能。Bi2Te3 薄膜的电沉积使用标准的三电极电池在恒电位模式下进行，然后在 300-500°C 下进行热退火。X 射线衍射和电子探针 X 射线微量分析结果表明，在沉积在 TiN 涂层 SS 衬底上的退火膜中没有发生来自 SS 衬底的杂质扩散。然而，由于 Te 原子从薄膜表面优先蒸发，Bi2Te3 到 Bi4Te5 的结晶相变发生在较高的退火温度下，导致薄膜的热电性能恶化。结果，在 TiN 涂层 SS 衬底上形成的 300°C 退火膜显示出最高的功率因数为 4.4 μW/(cm·K2)，大约是在裸露衬底上形成的相应膜的四倍。 SS 基材。因此，TiN 涂层和最佳退火温度提高了电沉积 Bi2Te3 薄膜的热电性能。在 TiN 涂层 SS 衬底上形成的 300°C 退火膜显示出最高的功率因数为 4.4 μW/(cm·K2)，大约是在裸 SS 衬底上形成的相应膜的四倍。因此，TiN 涂层和最佳退火温度提高了电沉积 Bi2Te3 薄膜的热电性能。在 TiN 涂层 SS 衬底上形成的 300°C 退火膜显示出最高的功率因数为 4.4 μW/(cm·K2)，大约是在裸 SS 衬底上形成的相应膜的四倍。因此，TiN 涂层和最佳退火温度提高了电沉积 Bi2Te3 薄膜的热电性能。