Ligand assisted swelling–deswelling microencapsulation (LASDM) for stable, color tunable perovskite–polymer composites

Metal halide perovskite nanocrystals (PNCs), with excellent electronic and optical properties, are promising for a variety of optoelectronic and photonic applications. However, the instability issue still impedes their practical applications. Here a ligand-assisted swelling–deswelling microencapsulation (LASDM) strategy is proposed and evaluated for improving the stability and photoluminescence (PL) performance of PNCs. With ligand assistance, well dispersed and intimately passivated PNCs in polymer matrices are obtained. Compared with the previously reported swelling–deswelling microencapsulation (SDM) strategy, the proposed method can provide better nanocrystal size control and surface coordination. Thus, full-color perovskite–polymer composites (PPCs) with unprecedented environmental stability can be achieved and concentration quenching can be avoided in polymer matrices. The excellent color purity, color tunability, optical density variability and environmental stability make PPCs highly promising for a range of PL applications, such as tailored lighting and transparent projection displays. Moreover, the simple, low cost, scalable process and the compatibility of this method with a group of polymer matrices should pave the way for PPCs to meet the requirements for practical use.