Zhou Liangliang, Sun Chuli, Li Xueming, Tang Libin, Guo Wei, Luo Lin, Zhang Meng, Teng Kar Seng, Qian Fuli, Lu Chaoyu, Liang Jing, Yao Yugui, Lau Shu Ping
Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials, Ministry of Education, Yunnan Normal University, Kunming, 650500, People's Republic of China.
School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
Nanoscale Res Lett. 2020 Jan 28;15(1):20. doi: 10.1186/s11671-020-3250-1.
Tantalum disulfide (TaS) 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-TaS quantum dots (1 T-TaS QDs) by top-down method. Herein, we prepared the TaS 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 TaS QDs exhibited ultraviolet absorption at 283 nm. Furthermore, we found that dimension reduction of TaS 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 TaS QDs have unique and extraordinary optical properties. Moreover, the low-cost, facile method of producing high quality TaS QDs in this work is ideal for mass production to ensure commercial viability of devices based on this material. TaS 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 TaS has led to a transition from indirect to direct band gap that results in the unique and extraordinary optical properties (PL QY: 45.6%).
二硫化钽（TaS）二维薄膜材料因其独特的光学和电学性质而备受关注。在这项工作中，我们报告了通过自上而下的方法制备1T-TaS量子点（1T-TaS QDs）。在此，我们通过有效的超声液相剥离法制备了单分散粒径约为3nm的TaS量子点。对所制备的TaS量子点使用紫外-可见光谱、光致发光光谱和光致发光激发光谱技术进行光学研究，结果表明其在283nm处有紫外吸收。此外，我们发现TaS的尺寸减小导致了带隙的改变，即从间接带隙转变为直接带隙，这可以用第一性原理计算来解释。以奎宁为参比，荧光量子产率为45.6%。因此，我们的结果表明TaS量子点具有独特而非凡的光学性质。此外，本工作中低成本、简便的高质量TaS量子点制备方法对于大规模生产以确保基于该材料的器件的商业可行性而言是理想的。通过超声液相剥离法制备了单分散粒径约为3nm的TaS量子点，发现TaS的尺寸减小导致了从间接带隙到直接带隙的转变，从而产生了独特而非凡的光学性质（光致发光量子产率：45.6%）。
