Influence of periodic flow field on synthesis of perovskite nanocrystals: Synthetic pathway and productivity

Abstract

Here it was demonstrated that series–parallel reaction pathway for CsPbBr3 and Cs4PbBr6 perovskite nanocrystals (PNCs) were selective by the periodic flow fields as well as precursor ratio. The periodic Taylor vortex flows (PTVFs) in a Couette-Taylor batch reactor (BR) were applied for controlling the synthetic pathway of PNCs and the random turbulent eddy flow (RTEF) in a stirred tank BR was also used for comparison. The PTVFs in the Couette-Taylor BR promoted not only the formation reaction of CsBr from the reaction between Cs-oleate (Cs-OA) and PbBr2 but also the reaction between CsBr and the remained PbBr2. As a result, the CsPbBr3 and Cs4PbBr6 PNCs could be selectively formed according to the ratio of Cs-OA:PbBr2 under the PTVFs in the Couette-Taylor BR, whereas they couldn’t under the RTEF in the stirred tank BR. In addition, the production yield of CsPbBr3 and Cs4PbBr6 PNCs in Couette-Taylor BR increased up to 30 % and 57 %, respectively, compared to their yield in the stirred tank BR due to the effective micro-mixing and shear dispersion of PNCs.