Efficient purification method for CsPbX3 perovskite quantum dots

Abstract

CsPbX3 perovskite quantum dots (QDs) have attracted increasing attention for the applications of lighting and display due to their excellent properties. Although the preparation of perovskite QDs has been widely developed, there is still not a universal and efficient method to purify perovskite QDs, which is due to the labile ionic characteristics of the perovskites. Here, a new purification method is proposed by using the addition of a new antisolvent-dimethicone oil (DMO). Compared to the two commonly used purification methods (direct centrifugation and centrifugation with ethyl acetate antisolvent), the sample purified by DMO addition shows the highest photoluminescence quantum yield (PLQY) and stability. Besides, the yield of the samples obtained from DMO addition is also the highest. This new purification method is also suitable for the products prepared by the room temperature method, where large amounts of QDs with high PLQY can be acquired. Furthermore, a simple differential centrifugation method is designed based on this anti-solvent. Size-selected perovskite QDs with narrow size distribution are obtained from this differential centrifugation method.