Tantalum disulfide quantum dots: preparation, structure, and properties
Liangliang Zhou, Chuli Sun, Xueming Li, Libin Tang, Wei Guo, Lin Luo, Meng Zhang, Kar Seng Teng, Fuli Qian, Chaoyu Lu, Jing Liang, Yugui Yao, Shu Ping Lau
Abstract
Abstract Tantalum disulfide (TaS 2 ) 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 2 quantum dots (1 T-TaS 2 QDs) by top-down method. Herein, we prepared the TaS 2 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 2 QDs exhibited ultraviolet absorption at 283 nm. Furthermore, we found that dimension reduction of TaS 2 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 2 QDs have unique and extraordinary optical properties. Moreover, the low-cost, facile method of producing high quality TaS 2 QDs in this work is ideal for mass production to ensure commercial viability of devices based on this material. Graphical abstract TaS 2 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 2 has led to a transition from indirect to direct band gap that results in the unique and extraordinary optical properties (PL QY: 45.6%).