Tantalum disulfide (TaS2) two-dimensional film material has attracted wide attention due to its unique optical and electrical properties. In this work, we report the preparation of 1 T-TaS2 quantum dots (1 T-TaS2 QDs) by top-down method. Herein, we prepared the TaS2 QDs having a monodisperse grain size of around 3 nm by an effective ultrasonic liquid phase exfoliation method. Optical studies using UV-Vis, PL, and PLE techniques on the as-prepared TaS2 QDs exhibited ultraviolet absorption at 283 nm. Furthermore, we found that dimension reduction of TaS2 has led to a modification of the band gap, namely a transition from indirect to direct band gap, which is explained using first-principle calculations. By using quinine as reference, the fluorescence quantum yield is 45.6%. Therefore, our results suggest TaS2 QDs have unique and extraordinary optical properties. Moreover, the low-cost, facile method of producing high quality TaS2 QDs in this work is ideal for mass production to ensure commercial viability of devices based on this material. TaS2 quantum dots having a monodisperse grain size of around 3 nm have been prepared by an ultrasonic liquid phase exfoliation method, it has been found that the dimension reduction of TaS2 has led to a transition from indirect to direct band gap that results in the unique and extraordinary optical properties (PL QY: 45.6%).

中文翻译：

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二硫化钽量子点：制备，结构和性质。

二硫化钽（TaS2）二维薄膜材料因其独特的光学和电学性能而受到广泛关注。在这项工作中，我们报告了通过自上而下的方法制备1个T-TaS2量子点（1个T-TaS2 QD）。在这里，我们通过有效的超声液相剥落法制备了单分散晶粒尺寸约为3 nm的TaS2 QD。在制备的TaS2 QD上使用UV-Vis，PL和PLE技术进行的光学研究显示出在283 nm处的紫外线吸收。此外，我们发现TaS2的尺寸减小导致带隙的改变，即从间接带隙到直接带隙的转变，这可以用第一原理计算来解释。以奎宁为参考，荧光量子产率为45.6％。因此，我们的结果表明TaS2 QD具有独特而卓越的光学性能。此外，这项工作中生产高质量TaS2 QD的低成本，简便方法是批量生产的理想选择，以确保基于这种材料的设备的商业可行性。通过超声液相剥落法制备了单分散晶粒尺寸约为3 nm的TaS2量子点，发现TaS2的尺寸减小导致了从间接带隙到直接带隙的转变，从而导致独特的非凡的光学性能（Q QY：45.6％）。