In-situ synthesis of MAPbBr3 perovskite quantum dot-polycaprolactone composites with enhanced photoluminescence quantum yield and stability

Polymer encapsulation is regarded as an efficient strategy to enhance the stability of perovskite quantum dots (PQDs), and also endows the perovskites with advantages in mechanical properties and processibility. In this work, polymer encapsulation was achieved by in-situ synthesis of PQDs in polycaprolactone (PCL) polymer, which avoiding time-consuming process of blending polymer with PQDs. Moreover, besides of acting as encapsulation matrix, PCL in toluene could provide large nucleation sites for PQDs formation, resulting in the relatively smaller PQDs size and enhanced photoluminescence quantum yield (PLQY) with respect to the composites prepared by physical blending. Profiting from PCL encapsulation, the as-synthesized PQDs-PCL composites exhibited enhanced stability against UV light, water and heat. The strong interaction between PQDs and PCL in composites with high PCL concentration could endow them with more significantly improved PL stability under UV-light illumination and relatively better mechanical properties compared to the composites with high PQDs concentration. This work provides an efficient method to synthesize PQDs-polymer composites with enhanced PLQY and stability, which would promote practical applications of PQDs materials in the optoelectronic applications.