Tantalum disulfide quantum dots: preparation, structure, and properties

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%). [Image: see text]