Ultra-small-size, highly efficient and stable CsPbBr3 quantum dots synthesized by using a cesium-dodecyl benzene sulfonic acid solution

All inorganic colloid CsPbX3 (X = Cl,Br,I) perovskite quantum dots (PeQDs) have become a promising new optoelectric material due to their excellent optical properties. However, the implementation of strong quantum constraints in PeQDs still faces great challenges, and there is still a lack of reliable methods to accurately control the PeQD size and luminescence performance. Here, ultra-small-size and highly luminous CsPbBr3 PeQDs have been prepared by hot injection method with a novel synthesis strategy. A cesium and ligand combined compound of cesium-dodecyl benzene sulfonic acid (Cs-DBSA) is employed as Cs and ligand sources concurrently. The ultra-small-size of CsPbBr3 PeQDs can be effectually controlled by the Cs-DBSA solution concentration. In particular, the synthesis route we developed can be terminated within 15 s after hot injection processing, which is rather different from previously reported methods including mechanical grinding, low temperature, and great Br/Pb ratio methods. Typical colloidal PeQDs show excellent comprehensive performance that having a minimum size up to 1.8 nm, unimodal photoluminescence (PL) with peak at 448.8 nm, high photoluminescence quantum yield (PLQY) up to 100%, and good light and color stabilities. As a healthy light source, spectral intensity uniformly distributed white-light-emitting diodes (WLED) have been realized by using the CsPbBr3 PeQDs to increase components of cyan light. The above results show that our proposed synthesis strategy is simple, rapid and effective, which is a significant step forward in the field of small-size PeQDs, and helpful for realizing large-scale industrial production of PeQDs.